Practical and Efficient Suzuki−Miyaura Cross-Coupling of 2-Iodocycloenones with Arylboronic Acids Catalyzed by Recyclable Pd(0)/C
摘要:
The first Suzuki-Miyaura cross-coupling of 2-iodocycloenones with arylboronic acids catalyzed by 10% Pd(O)/C is described as an interesting alternative to classical homogeneous conditions. Most of the substrate reacted under mild condition at 25 degrees C under air in aqueous DME. The conditions described tolerate a wide range of iodoenones and boronic acids. Notably, the procedure features inexpensive reagents and solvents with low toxicity rendering the method environmentally benign. Additionally 10% Pd(O)/C could be recovered and efficiently reused at least five times without significant alteration of the yields of the cross-coupled product.
A rhodium carbonyl complex, [RhCl(CO)(2)](2), serves as a catalyst of the intra- and inter-molecular Pauson-Khand reaction. By the use of the rhodium catalyst, cyclopentenone derivatives are prepared from various 1,6- and 1,7-enynes under 1 arm of CO. Furthermore, this rhodium-catalyzed reaction is accelerated by reducing partial pressure of CO to less than 1 atm. (C) 2001 Elsevier Science B.V. All rights reserved.
2 + 1] cycloaddition takes place in the rhodium-catalyzed reaction of 1,6-enynes with borylsilanes bearing an alkoxy group on the silicon atoms, which react as synthetic equivalents of silylene. The reaction proceeds efficiently in 1,2-dichloroethane at 80–110 °C in the presence of a rhodium catalyst bearing bis(diphenylphosphino)methane (DPPM) as a ligand to afford 1-silacyclopent-2-enes in good to
Stereoselective Nickel-Catalyzed [2+2+2] Cycloaddition of Enynes and Arynes
作者:Mark Lautens、David Candito
DOI:10.1055/s-0030-1261171
日期:2011.9
Examples of stereoselective reactions of aryne intermediates are rare in the literature. A stereoselectivenickel-catalyzed [2+2+2] cycloaddition of 1,6-enynes with aryne intermediates is reported. Excellent stereoselectivities were observed when a substituent is adjacent to the olefin moiety resulting in trans- stereochemistry in the products. This reaction is capable of generating much complexity
A rhodium dinuclear carbonyl complex, [RhCl(CO)2]2, serves as a catalyst of the intramolecularPauson-Khandreaction. 1,6-Enynes are converted to cyclopentenone derivatives in high yield by heating in the presence of the catalyst under an atmospheric pressure of CO.
铑双核羰基络合物 [RhCl(CO)2]2 可作为分子内 Pauson-Khand 反应的催化剂。1,6-烯炔通过在催化剂的存在下在大气压的 CO 下加热以高产率转化为环戊烯酮衍生物。
Ru<sub>3</sub>(CO)<sub>12</sub>-Catalyzed Cyclocarbonylation of 1,6-Enynes to Bicyclo[3.3.0]octenones