作者:Christopher A. Discolo、Eric E. Touney、Sergey V. Pronin
DOI:10.1021/jacs.9b10645
日期:2019.11.6
Asymmetric intramolecular hydrofunctionalization of tertiary allylic alcohols is described. This metal hydride-mediated catalytic radical-polar crossover reaction delivers corresponding epoxides in good to high enantioselectivity and constitutes the first example of asymmetric hydrogen atom transfer-initiated process. A series of modified cobalt salen complexes has proven optimal for achieving good
Synthesis of Carbo- and Heterocyclic Aldehydes Bearing an Adjacent Donor Group ? Ozonolysis versus OsO4/KIO4-Oxidation
作者:Marko D. Mihovilovic、Markus Spina、Bernhard M�ller、Peter Stanetty
DOI:10.1007/s00706-004-0163-0
日期:2004.6
an ipso -methoxy group is investigated. The synthetic sequence is based on an initial Grignard addition of an olefin to a cyclic ketone followed by methylation of the resulting tertiary alcohol. The terminal olefin serves as precursor for the aldehyde functionality. Oxidation by ozonolysis turned out to depend significantly on the distance of the donor methoxy group. The observed side reactions could
A Practical Source of Chlorodifluoromethyl Radicals. Convergent Routes to <i>gem</i>-Difluoroalkenes and -dienes and (2,2-Difluoroethyl)-indoles, -azaindoles, and -naphthols
作者:Pierre Salomon、Samir Z. Zard
DOI:10.1021/ol501063a
日期:2014.6.6
The preparation of O-octadecyl-S-chlorodifluoromethyl xanthate from chlorodifluoroacetic acid and its use as a convenient source of chlordifluoromethyl radicals is described. This reagent may be used to access gem-difluoroalkenes and -dienes, as well as (2,2-difluoroethyl)-indolines, -indoles, and -naphthols.