An Oxidative [2,3]-Sigmatropic Rearrangement of Allylic Hydrazides
作者:Benjamin F. Strick、Devon A. Mundal、Regan J. Thomson
DOI:10.1021/ja2066219
日期:2011.9.14
The development of an efficient oxidative [2,3]-sigmatropicrearrangement of allylic hydrazides, via singlet N-nitrene intermediates, is reported. The requisite allylic hydrazide precursors are readily prepared and undergo smooth sigmatropic rearrangement upon exposure to iodosobenzene. The products of this novel transformation are shown to be useful precursors to a variety of compounds.
Allylic Substitution for Construction of a Chiral Quaternary Carbon Possessing an Aryl Group
作者:Chao Feng、Yuichi Kobayashi
DOI:10.1021/jo400248y
日期:2013.4.19
Phenylcopper reagents derived from 2:1 PhMgBr/Cu(acac)(2) and 3:1:1 PhMgBr/Cu(acac)(2)/ZnI2 were found to be highly reactive and regioselective in the allylic substitution of gamma,gamma-disubstituted secondary allylic picolinates designed for construction of a quaternary carbon, whereas the previous 2:1 ArMgBr/CuBr center dot Me2S reagent and that with ZnX2 were unsuccessful. The generality of the ArMgBr/Cu(acac)(2) reagent was examined with enantiomerically enriched allylic picolinates, which furnished quaternary carbons with high efficiency in >92% regioselectivity and >97% chirality transfer. Two cyclohexanes with a quaternary carbon were synthesized by using these reagents.