Consensus is growing among ecologists that energy and the factors influencing its utilization can play overarching roles in regulating large-scale patterns of biodiversity. The deep sea—the world's largest ecosystem—has simplified energetic inputs and thus provides an excellent opportunity to study how these processes structure spatial diversity patterns. Two factors influencing energy availability and use are chemical (productive) and thermal energy, here represented as seafloor particulate organic carbon (POC) flux and temperature. We related regional patterns of benthic molluscan diversity in the North Atlantic to these factors, to conduct an explicit test of species–energy relationships in the modern day fauna of the deep ocean. Spatial regression analyses in a model-averaging framework indicated that POC flux had a substantially higher relative importance than temperature for both gastropods and protobranch bivalves, although high correlations between variables prevented definitive interpretation. This contrasts with recent research on temporal variation in fossil diversity from deep-sea cores, where temperature is generally a more significant predictor. These differences may reflect the scales of time and space at which productivity and temperature operate, or differences in body size; but both lines of evidence implicate processes influencing energy utilization as major determinants of deep-sea species diversity.
species–energy; productivity; temperature; mollusc; diversity
Glacio-marine fjords occur widely at high latitudes and have been extensively studied in the Arctic, where heavy meltwater inputs and sedimentation yield low benthic faunal abundance and biodiversity in inner-middle fjords. Fjord benthic ecosystems remain poorly studied in the subpolar Antarctic, including those in extensive fjords along the West Antarctic Peninsula (WAP). Here we test ecosystem predictions from Arctic fjords on three subpolar, glacio-marine fjords along the WAP. With seafloor photographic surveys we evaluate benthic megafaunal abundance, community structure, and species diversity, as well as the abundance of demersal nekton and macroalgal detritus, in soft-sediment basins of Andvord, Flandres and Barilari Bays at depths of 436–725 m. We then contrast these fjord sites with three open shelf stations of similar depths. Contrary to Arctic predictions, WAP fjord basins exhibited 3 to 38-fold greater benthic megafaunal abundance than the open shelf, and local species diversity and trophic complexity remained high from outer to inner fjord basins. Furthermore, WAP fjords contained distinct species composition, substantially contributing to beta and gamma diversity at 400–700 m depths along the WAP. The abundance of demersal nekton and macroalgal detritus was also substantially higher in WAP fjords compared to the open shelf. We conclude that WAP fjords are important hotspots of benthic abundance and biodiversity as a consequence of weak meltwater influences, low sedimentation disturbance, and high, varied food inputs. We postulate that WAP fjords differ markedly from their Arctic counterparts because they are in earlier stages of climate warming, and that rapid warming along the WAP will increase meltwater and sediment inputs, deleteriously impacting these biodiversity hotspots. Because WAP fjords also provide important habitat and foraging areas for Antarctic krill and baleen whales, there is an urgent need to develop better understanding of the structure, dynamics and climate-sensitivity of WAP subpolar fjord ecosystems.
Cold seep communities with distinctive chemoautotrophic fauna occur where hydrocarbon-rich fluids escape from the seabed. We describe community composition, population densities, spatial extent, and within-region variability of epifaunal communities at methane-rich cold seep sites on the Hikurangi Margin, New Zealand. Using data from towed camera transects, we match observations to information about the probable life-history characteristics of the principal fauna to develop a hypothetical succession sequence for the Hikurangi seep communities, from the onset of fluid flux to senescence. New Zealand seep communities exhibit taxa characteristic of seeps in other regions, including predominance of large siboglinid tubeworms, vesicomyid clams, and bathymodiolin mussels. Some aspects appear to be novel; however, particularly the association of dense populations of ampharetid polychaetes with high-sulphide, high-methane flux, soft-sediment microhabitats. The common occurrence of these ampharetids suggests they play a role in conditioning sulphide-rich sediments at the sediment-water interface, thus facilitating settlement of clam and tubeworm taxa which dominate space during later successional stages. The seep sites are subject to disturbance from bottom trawling at present and potentially from gas hydrate extraction in future. The likely life-history characteristics of the dominant megafauna suggest that while ampharetids, clams, and mussels exploit ephemeral resources through rapid growth and reproduction, lamellibrachid tubeworm populations may persist potentially for centuries. The potential consequences of gas hydrate extraction cannot be fully assessed until extraction methods and target localities are defined but any long-term modification of fluid flow to seep sites would have consequences for all chemoautotrophic fauna.
We report the results from the first experimental study of the fate of whale and wood remains on the Antarctic seafloor. Using a baited free-vehicle lander design, we show that whale-falls in the Antarctic are heavily infested by at least two new species of bone-eating worm, Osedax antarcticus sp. nov. and Osedax deceptionensis sp. nov. In stark contrast, wood remains are remarkably well preserved with the absence of typical wood-eating fauna such as the xylophagainid bivalves. The combined whale-fall and wood-fall experiment provides support to the hypothesis that the Antarctic circumpolar current is a barrier to the larvae of deep-water species that are broadly distributed in other ocean basins. Since humans first started exploring the Antarctic, wood has been deposited on the seafloor in the form of shipwrecks and waste; our data suggest that this anthropogenic wood may be exceptionally well preserved. Alongside the new species descriptions, we conducted a comprehensive phylogenetic analyses of Osedax, suggesting the clade is most closely related to the frenulate tubeworms, not the vestimentiferans as previous reported.
whale-fall; wood-fall; Annelida; Polychaeta; Siboglinidae; Xylophaga
Paravalvular leak following a mitral valve replacement is a complication seen in approximately 1 of 10 replacements. The corrective method has traditionally been reoperation. Septal occluder devices are more commonly being utilized as an alternative percutaneous correction method. We report the use of septal occluder devices in the repair of mitral paravalvular leak in two patients at severely high EuroSCORE II mortality risk. In both patients, the occluder devices became unstable, leading to a recurrence of severe paravalvular leak.
Minimally invasive; Valve repair; Percutaneous; Mitral valve; Valvular leak
This study sought to evaluate the impact of frailty in older adults undergoing transcatheter aortic valve replacement (TAVR) for symptomatic aortic stenosis.
Frailty status impacts prognosis in older adults with heart disease; however, the impact of frailty on prognosis after TAVR is unknown.
Gait speed, grip strength, serum albumin, and activities of daily living status were collected at baseline and used to derive a frailty score among patients who underwent TAVR procedures at a single large-volume institution. The cohort was dichotomized on the basis of median frailty score into frail and not frail groups. The impact of frailty on procedural outcomes (stroke, bleeding, vascular complications, acute kidney injury, and mortality at 30 days) and 1-year mortality was evaluated.
Frailty status was assessed in 159 subjects who underwent TAVR (age 86 ± 8 years, Society of Thoracic Surgery Risk Score 12 ± 4). Baseline frailty score was not associated with conventionally ascertained clinical variables or Society of Thoracic Surgery score. Although high frailty score was associated with a longer post-TAVR hospital stay when compared with lower frailty score (9 ± 6 days vs. 6 ± 5 days, respectively, p = 0.004), there were no significant crude associations between frailty status and procedural outcomes, suggesting adequacy of the standard selection process for identifying patients at risk for periprocedural complications after TAVR. Frailty status was independently associated with increased 1-year mortality (hazard ratio: 3.5, 95% confidence interval: 1.4 to 8.5, p = 0.007) after TAVR.
Frailty was not associated with increased periprocedural complications in patients selected as candidates to undergo TAVR but was associated with increased 1-year mortality after TAVR. Further studies will evaluate the independent value of this frailty composite in older adults with aortic stenosis.
aortic stenosis; frailty; transcatheter valve
In the transcatheter aortic valve replacement era, characterization of functional status in older adults with aortic stenosis (AS) is essential. Gait speed (GS) is emerging as a marker of frailty and predictor of outcomes in older adults undergoing cardiovascular intervention. The objective of this study was to delineate the prevalence of slow GS, evaluate the association of GS with factors used in standard cardiovascular assessments, and evaluate the association of GS with dependence in activities of daily living (ADLs) in older adults with AS.
We hypothesized that gait speed would not be associated with clinical factors, but would be associated with ADLs.
We evaluated GS, ADLs dependence, and Society of Thoracic Surgery score along with clinical and functional assessments in 102 older adults with AS being evaluated for transcatheter valve. Gait speed <0.5 m/s was considered slow, and GS ≥0.5 m/s was considered preserved. We assessed the association of covariates with GS as well as with ADLs dependence.
Median GS was 0.37 m/s (interquartile range, 0.0–0.65 m/s). Sixty-four (63%) subjects had slow GS. Of commonly employed clinical covariates, only prior coronary intervention and serum albumin were weakly associated with GS. However, GS was independently associated with ADLs dependence (Odds ratio: 1.52 [1.21–1.91] for every 0.1 m/s decrease in GS; P = 0.0003).
Although the prevalence of slow GS in a population of elderly patients with severe AS being screened for transcatheter valve was high, there were only weak associations between GS and other risk stratifying tools. The strong association between GS and dependent functional status suggests that assessment of gait speed is a useful, objectively measurable, risk stratification tool in this population.
No simplified bedside risk scores have been created to predict long-term mortality after coronary artery bypass graft (CABG) surgery.
Methods and Results
The New York State’s Cardiac Surgery Reporting System was used to identify 8,597 patients who underwent isolated CABG surgery in July-December 2000. The National Death Index was used to ascertain patients’ vital status through December 31, 2007. A Cox proportional hazards model was fit to predict death following CABG surgery using pre-procedural risk factors. Then points were assigned to significant predictors of death based on the values of their regression coefficients. For each possible point total, the predicted risks of death at years 1, 3, 5, and 7 were calculated. It was found that the 7-year mortality rate was 24.2% in the study population. Significant predictors of death included age, body mass index, ejection fraction, unstable hemodynamic state or shock, left main coronary artery disease, cerebrovascular disease, peripheral arterial disease, congestive heart failure, malignant ventricular arrhythmia, chronic obstructive pulmonary disease, diabetes, renal failure, and history of open heart surgery. The points assigned to these risk factors ranged from 1 to 7; and possible point totals for each patient ranged from 0 to 28. The observed and predicted risks of death at years 1, 3, 5, and 7 across patient groups stratified by point totals were highly correlated.
The simplified risk score accurately predicted the risk of mortality following CABG surgery, and can be used for informed consent and as an aid in determining treatment choice.
CABG; follow-up studies; mortality; risk score
Lithodid crabs (and other skeleton-crushing predators) may have been excluded from cold Antarctic continental shelf waters for more than 14 Myr. The west Antarctic Peninsula shelf is warming rapidly and has been hypothesized to be soon invaded by lithodids. A remotely operated vehicle survey in Palmer Deep, a basin 120 km onto the Antarctic shelf, revealed a large, reproductive population of lithodids, providing the first evidence that king crabs have crossed the Antarctic shelf. DNA sequencing and morphology indicate the lithodid is Neolithodes yaldwyni Ahyong & Dawson, previously reported only from Ross Sea waters. We estimate a N. yaldwyni population density of 10 600 km−2 and a population size of 1.55 × 106 in Palmer Deep, a density similar to lithodid populations of commercial interest around Alaska and South Georgia. The lithodid occurred at depths of more than 850 m and temperatures of more than 1.4°C in Palmer Deep, and was not found in extensive surveys of the colder shelf at depths of 430–725 m. Where N. yaldwyni occurred, crab traces were abundant, megafaunal diversity reduced and echinoderms absent, suggesting that the crabs have major ecological impacts. Antarctic Peninsula shelf waters are warming at approximately 0.01°C yr−1; if N. yaldwyni is currently limited by cold temperatures, it could spread up onto the shelf (400–600 m depths) within 1–2 decades. The Palmer Deep N. yaldwyni population provides an important model for the potential invasive impacts of crushing predators on vulnerable Antarctic shelf ecosystems.
lithodids; invasion; Antarctic; climate warming; bioturbation; biodiversity loss
Mitral valve annular calcification has long been a challenge in repairing posterior mitral valve prolapse. Folding valvuloplasty of the posterior leaflet without resection provides a means of circumventing common procedural complications. This report demonstrates the success of folding valvuloplasty without resection in the treatment of mitral valve prolapse and severe annular calcification.
Mitral valve repair; Valvuloplasty; Calcification mitral annulus
In selected patients undergoing cardiac surgery, our research group previously showed that optimized temporary biventricular pacing can increase cardiac output one hour after weaning from cardiopulmonary bypass. Whether pacing is effective after beating-heart surgery is unknown. Accordingly, in this study we examined the feasibility of temporary biventricular pacing after off-pump coronary artery bypass grafting.
The effects of optimized pacing on cardiac output were measured with an electromagnetic aortic flow probe at the conclusion of surgery in 5 patients with a preoperative mean left ventricular ejection fraction of 0.26 (range, 0.15–0.35). Atrioventricular (7) and interventricular (9) delay settings were optimized in randomized order.
Cardiac output with optimized biventricular pacing was 4.2 ± 0.7 L/min; in sinus rhythm, it was 3.8 ± 0.5 L/min. Atrial pacing at a matched heart rate resulted in cardiac output intermediate to that of sinus rhythm and biventricular pacing (4 ± 0.6 L/min). Optimization of atrioventricular and interventricular delay, in comparison with nominal settings, trended toward increased flow.
This study shows that temporary biventricular pacing is feasible in patients with preoperative left ventricular dysfunction who are undergoing off-pump coronary artery bypass grafting. Further study of the possible clinical benefits of this intervention is warranted.
Arrhythmias, cardiac/therapy; cardiac pacing, artificial/methods; cardiac output, low/therapy; heart failure/therapy; stroke volume; ventricular dysfunction, left/complications/prevention & control
The aim of this study was to compare the cost and effectiveness of a minimally invasive (MI) versus traditional sternotomy (ST) approach for mitral valve surgery (MVS).
From 1/1/03–12/31/08, 847 patients underwent isolated MVS at our institution. Propensity matching on 22 clinical variables was carried out to generate a study cohort of 434 patients (217 matched pairs). Direct and indirect costs from the hospital perspective were retrospectively obtained from our finance department. Total hospital costs were further stratified into 13 standardized institutional billing categories. In addition, data on morbidity, mortality, discharge location, hospital readmissions within one year, and freedom from reoperation were obtained.
Compared to ST, MIMVS was associated with a $9,054 ± 3,302 lower mean total hospital cost (p=0.006), driven largely by a reduction in direct (p=0.003) versus indirect costs (p=0.06). Among the 13 billing categories, MIMVS was associated with a significant reduction in costs of: cardiac imaging (p=0.004), laboratory tests (p=0.005), boarding and nursing (p=0.001), and radiology (p=0.002). More patients in the ST group required intubation for > 72 hours (p=0.019); however, there were no differences in morbidity or long-term survival (p=0.334). There were a higher proportion of MI patients discharged home with no nursing services (p=0.018), and a higher proportion of readmissions among ST patients within one year (p=0.023). There were no differences in freedom from reoperation between groups (p=0.574).
With equivalent efficacy across a range of measures and lower costs compared to ST, MIMVS represents a cost-saving strategy for MVS.
There is little information on the relative survival of coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention with stenting with follow-up longer than 5 years. This study tested the hypothesis that CABG surgery is associated with lower risk of long-term (8-year) mortality than stenting with bare-metal stents for multivessel coronary disease.
We identified 18,359 patients with multivessel disease who underwent isolated CABG surgery and 13,377 patients who received BMS in 1999–2000 in New York, and followed their vital status through 2007 using the National Death Index. We matched CABG and stent patients on the number of diseased coronary vessels, proximal left anterior descending (LAD) artery disease, and propensity of undergoing CABG surgery based on numerous patient characteristics, and compared the survival after the two procedures.
In the 7,235 pairs of matched patients, the overall 8-year survival rates were 78.0% for CABG surgery and 71.2% for stenting (hazard ratio = 0.68, 95% confidence interval: 0.64 to 0.74, P<0.001). For anatomic groups classified by the number of diseased vessels and proximal LAD involvement, the hazard ratios ranged from 0.53 (P<0.001) for patients with 3-vessel disease involving proximal LAD artery disease to 0.78 (P=0.05) for patients with 2-vessel disease but no disease in the LAD artery. A lower risk of death after CABG surgery was observed in all subgroups stratified by a number of baseline risk factors.
CABG surgery is associated with lower risk of death than stenting with bare-metal stents for multivessel coronary disease.
Coronary artery bypass grafts; Coronary percutaneous interventions; Outcomes
Sediments associated with hydrothermal venting, methane seepage and large organic falls such as whale, wood and plant detritus create deep-sea networks of soft-sediment habitats fueled, at least in part, by the oxidation of reduced chemicals. Biological studies at deep-sea vents, seeps and organic falls have looked at macrofaunal taxa, but there has yet to be a systematic comparison of the community-level attributes of sediment macrobenthos in various reducing ecosystems. Here we review key similarities and differences in the sediment-dwelling assemblages of each system with the goals of (1) generating a predictive framework for the exploration and study of newly identified reducing habitats, and (2) identifying taxa and communities that overlap across ecosystems. We show that deep-sea seep, vent and organic-fall sediments are highly heterogeneous. They sustain different geochemical and microbial processes that are reflected in a complex mosaic of habitats inhabited by a mixture of specialist (heterotrophic and symbiont-associated) and background fauna. Community-level comparisons reveal that vent, seep and organic-fall macrofauna are very distinct in terms of composition at the family level, although they share many dominant taxa among these highly sulphidic habitats. Stress gradients are good predictors of macrofaunal diversity at some sites, but habitat heterogeneity and facilitation often modify community structure. The biogeochemical differences across ecosystems and within habitats result in wide differences in organic utilization (i.e., food sources) and in the prevalence of chemosynthesis-derived nutrition. In the Pacific, vents, seeps and organic-falls exhibit distinct macrofaunal assemblages at broad-scales contributing to ß diversity. This has important implications for the conservation of reducing ecosystems, which face growing threats from human activities.
Over the past decade, minimally invasive cardiothoracic surgery (MICS) has grown in popularity. This growth has been driven, in part, by a desire to translate many of the observed benefits of minimal access surgery, such as decreased pain and reduced surgical trauma, to the cardiac surgical arena. Initial enthusiasm for MICS was tempered by concerns over reduced surgical exposure in highly complex operations and the potential for prolonged operative times and patient safety. With innovations in perfusion techniques, refinement of transthoracic echocardiography and the development of specialized surgical instruments and robotic technology, cardiac surgery was provided with the necessary tools to progress to less invasive approaches. However, much of the early literature on MICS focused on technical reports or small case series. The safety and feasibility of MICS have been demonstrated, yet questions remain regarding the relative efficacy of MICS over traditional sternotomy approaches. Recently, there has been a growth in the body of published literature on MICS long-term outcomes, with most reports suggesting that major cardiac operations that have traditionally been performed through a median sternotomy can be performed through a variety of minimally invasive approaches with equivalent safety and durability. In this article, we examine the technological advancements that have made MICS possible and provide an update on the major areas of cardiac surgery where MICS has demonstrated the most growth, with consideration of current and future directions.
minimally invasive cardiothoracic surgery; outcomes
Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42°01′ S, 173°03′ E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study.
submarine canyons; benthic biomass hotspots; molpadiid holothurians; macrourid fishes; eastern New Zealand margin
Aryl bromides and iodides in the presence of catalytic amounts of a palladacycle derived from acetophenone oxime and 2 equivalents of potassium acetate react with ethylene under ambient pressure (15–30 psi) to give the corresponding vinylarenes. The reactions work with both electron-deficient and electron-rich aryl compounds and tolerate wide variety of common functional groups. Vinyl bromides lead to 1,3-dienes in moderate yields.
A three-step procedure for the synthesis of 2-arylpropionic acids (profens) from vinyl arenes in nearly enantiomerically pure form has been developed. Excellent yields (>97%), regioselectivities (>99%), and enantioselectivities (>97% ee) for the desired branched products were obtained in the asymmetric hydrovinylation reactions of vinyl arenes, and the products from these reactions were transformed into 2-arylpropionic acids via oxidative degradation. Subsequent Curtius or Schmidt rearrangements of these acids provided highly valued 1-arylethyl amines, including a prototypical primary amine with an α-chiral tertiary N-alkyl group, in very good yields.
Over the past decade, minimally invasive cardiac surgery (MICS) has emerged as an accepted approach for the management of cardiac disease that requires a surgical solution. We report the results of an 8-year, single-institution experience with MICS.
Between January 1, 2000 and December 31, 2007, a total of 910 patients underwent MICS. Major cases included aortic valve procedures (71, 7.8%), coronary artery bypass grafting (96, 10.5%), atrioseptal defect repair (103, 11.3%), and mitral valve procedures (507, 55.7%). Major outcomes of interest included the complication and mortality rates.
The mean age of the patients was 57 ± 15 years; the mean ejection fraction was 55% ± 11%; and the mean body mass index was 26.1 ± 4.9. Overall, 782 cases (85.9%) were performed through a mini-thoracotomy. Most of the cases were accomplished through central cannulation (765, 84.0%), and venous drainage was most commonly performed in a bicaval fashion (percutaneous superior vena cava and percutaneous inferior vena cava). The mean aortic cross-clamp and cardiopulmonary bypass (CPB) times were 58.1 ± 44.9 and 101.9 ± 66.8 min, respectively. Conversion to full sternotomy occurred in 10 patients, and the median length of stay in hospital was 6 days. The overall complication rate was 8.8%, and the 30-day mortality rate was 2.9%. In the multivariate logistic regression analysis, risk factors associated with in-hospital complications included age, CPB time, arterial cannulation location, conversion from off-CPB to on-CPB, hepatic insufficiency, and diabetes. In the multivariate hazards regression analysis, risk factors associated with mortality included postoperative stroke, renal failure, and sternal wound infection; CPB time; and previous surgery.
In our experience, minimally invasive approaches are effective and reproducible for a variety of cardiac operations, with acceptable operating time durations, morbidity, and mortality.
Fine tuning of the biaryl and amino moieties of Feringa’s phosphoramidite ligands yields structurally simpler, yet more efficient and selective, ligands for asymmetric hydrovinylation of vinylarenes and acylic 1,3-dienes. The enantioselectivities and yields observed in the formation of the 3-arylbutenes are among the highest for all asymmetric catalytic processes reported to date for the synthesis of intermediates for the widely used antiinflammatory 2-arylpropionic acids including naproxen, ibuprofen, fenoprofen, and flurbiprofen.
1-Alkylstyrenes undergo efficient hydrovinylation (addition of ethylene) in the presence of a Ni-catalyst prepared from [(allyl)NiBr]2, Na+ [BAr4]− (Ar = 3,5-bis-trifluromethylphenyl), and a phosphoramidite ligand giving products in excellent yields and enantioselectivities. In many cases phosphoramidites derived from achiral 2,2′-biphenol are almost as good as ligands derived from the more expensive enantiopure 2,2′-binaphthols. The hydrovinylation products, which carry two versatile latent functionalities, an aryl and a vinyl group, are potentially useful for the synthesis of several important natural products containing benzylic all-carbon quaternary centers.
alkenes; asymmetric catalysis; hydrovinylation; phosphoramidite ligands; nickel
Mono- and 2,2′-di-substituted terminal alkenes can be isomerized into the more stable internal Z- and E- alkenes by treating them with catalytic amounts of [(allyl)PdCl]2 or [(allyl)NiBr]2, a triarylphosphine and silver triflate at room temperature. The isomeric ratio (E:Z) depends on the alkenes, the (E)-isomer being the major one. The reaction is tolerant to a wide variety of functional groups including other reactive olefins. Unlike the more reactive Ir catalysts, monosubstituted alkenes give almost exclusively the 2-alkenes. Direct comparison to two of the best-known catalysts for this process, (Ir(PCy3)3]+ [BPh4]−, and Grubbs Generation II metathesis catalyst) is also reported.