3-Difluoromethylated 2,3-dihydrobenzoheteroles, 2,3-dihydrobenzofurans, 2,3-dihydrobenzothiophenes, and indolines were readily synthesized from ortho-heterosubstituted bromobenzenes, 2-bromophenols, 2-bromobenzenethiols, and 2-bromoanilines, respectively, in two steps: (1) gamma-selective allylic substitution of 3-bromo-3,3-difluoropropene with heteronucleophiles and (2) intramolecular radical cyclization of the resulting 3,3-difluoroallylic compounds.
Synthesis of Diverse α‐Fluoroalkoxyaryl Derivatives and Their Use for the Generation of Fluorinated Macrocycles
作者:Thomas J. Cogswell、Anders Dahlén、Laurent Knerr
DOI:10.1002/chem.201804440
日期:——
Introduction of difluorinated functionality has emerged as a powerful means for conformational design with minimal steric footprint. Synthetic approaches for the preparation of aryl difluoromethylene ether containing novel building blocks were established, enabling the inclusion of the aryl difluoromethylene ether system into macrocyclic scaffolds for the first time.
The synthesis of difluoromethylene-containing heterocycles was achieved via the palladium-catalyzed 1,1-difluoroallylation of heteronucleophiles followed by intramolecularHeck reaction. The allylic substitution of 3-bromo-3,3-difluoropropene was regioselectively accomplished by heteronucleophiles without rearrangement to give the corresponding 1,1-difluoroallylated compounds whose Heck cyclization