Electron-Deficient Olefin Ligands Enable Generation of Quaternary Carbons by Ni-Catalyzed Cross-Coupling
作者:Chung-Yang (Dennis) Huang、Abigail G. Doyle
DOI:10.1021/jacs.5b02503
日期:2015.5.6
A Ni-catalyzed Negishi cross-coupling with 1,1-disubstituted styrenyl aziridines has been developed. This method delivers valuable β-substituted phenethylamines via a challenging reductive elimination that affords a quaternary carbon. A novel electron-deficient olefin ligand, Fro-DO, proved crucial for achieving high rates and chemoselectivity for C-C bond formation over β-H elimination. This ligand
2‐disubstituted N‐sulfonylaziridines bearing OTBS groups and aryl groups at two different substitutions of the aziridine ring has been prepared. Based on them, a stepwise strategy involving ring opening of aziridines and C−H activation/cyclization has been developed for the generalsynthesis of spiroindoline pyrans and spiroindoline furans.
catalytic ligand for the PdII-catalyzed oxidative Heck reaction with high linear selectivity. The linear selectivity of CMP-1 is about 30 times higher than that of bipyridine-based monomer ligand. This work opens a new front of using CMP as an intriguing platform for developing highly efficient catalysts in controlling the regioselectivity in organic reactions.
Iridium(I)-Catalyzed Intramolecular Hydrocarbonation of Alkenes: Efficient Access to Cyclic Systems Bearing Quaternary Stereocenters
作者:David F. Fernández、Moisés Gulías、José L. Mascareñas、Fernando López
DOI:10.1002/anie.201705105
日期:2017.8.1
wide variety of cyclic systems featuring methyl-substituted quaternary stereocenters is described. The method relies on the use of a cationic IrI–bisphosphine catalyst, which promotes a carboxamide-assisted activation of an olefinic C(sp2)−H bond followed by exo-cyclization to a tethered 1,1-disubstituted alkene. The extension of the method to aromatic and heteroaromatic C−H bonds, as well as developments