Pd-Catalyzed Difluoromethylation of Vinyl Bromides, Triflates, Tosylates, and Nonaflates
作者:Dalu Chang、Yang Gu、Qilong Shen
DOI:10.1002/chem.201500551
日期:2015.4.13
Pd‐catalyzed difluoromethylation of di‐, tri‐ or tetra‐substituted vinyl bromides, triflates, tosylates and nonaflates under mild conditions is described. The reaction tolerates a wide range of functional groups, such as bromide, chloride, fluoride, ester, amine, nitrile, and protected carbonyl, thus providing a general route for the preparation of difluoromethylated alkenes.
Formation of Chiral Allylic Ethers via an Enantioselective Palladium-Catalyzed Alkenylation of Acyclic Enol Ethers
作者:Harshkumar H. Patel、Matthew B. Prater、Scott O. Squire、Matthew S. Sigman
DOI:10.1021/jacs.8b02751
日期:2018.5.9
palladium-catalyzed process to access highly functionalized, optically active allylic aryl ethers. A number of electron-deficient alkenyl triflates underwent enantioselective and site-selective coupling with acyclic aryl enol ethers in the presence of a chiral palladium catalyst. This transform provides chiral allylicether products in high yields and excellent enantiomeric ratios, furnishing a unique
Multimetallic Ni- and Pd-Catalyzed Cross-Electrophile Coupling To Form Highly Substituted 1,3-Dienes
作者:Astrid M. Olivares、Daniel J. Weix
DOI:10.1021/jacs.7b13601
日期:2018.2.21
synthesis of highly substituted 1,3-dienes from the coupling of vinyl bromides with vinyl triflates is reported for the first time. The coupling is catalyzed by a combination of (5,5'-bis(trifluoromethyl)-2,2'-bipyridine)NiBr2 and (1,3-bis(diphenylphosphino)propane)PdCl2 in the presence of a zinc reductant. This method affords tetra- and penta-substituted 1,3-dienes that would otherwise be difficult
Synthesis of Substituted Pyrazoles via Tandem Cross-Coupling/Electrocyclization of Enol Triflates and Diazoacetates
作者:David J. Babinski、Hector R. Aguilar、Raymond Still、Doug E. Frantz
DOI:10.1021/jo201042c
日期:2011.8.5
The synthesis of 3,4,5-trisubstituted pyrazoles via a tandem catalytic cross-coupling/electrocyclization of enoltriflates and diazoacetates is presented. The initial scope of this methodology is demonstrated on a range of differentially substituted acyclic and cyclic enoltriflates as well as an elaborated set of diazoacetates to provide the corresponding pyrazoles with a high degree of structural
Palladium-Catalyzed Enantioselective Heck Alkenylation of Acyclic Alkenols Using a Redox-Relay Strategy
作者:Harshkumar H. Patel、Matthew S. Sigman
DOI:10.1021/ja5130836
日期:2015.3.18
carbonyl group in high enantioselectivity. The success of this reaction is attributed to the use of electron-withdrawing alkenyl triflates, which offer selective β-hydride elimination followed by migration of the catalyst through the alkyl chain to give the alkenylated carbonyl products. The synthetic utility of the process is demonstrated by a two-step modification of a reaction product to yield a tricyclic