substrates 1 and 2 can be regioselectively converted into chiral allenyl alcohols 3 through the title reaction [Eq. (1)] with the synergetic reagent iPrSBEt2 and a chiral TiIV catalyst. The dramatic regioselectivity originates from the regulation of the equilibriumbetween propargyl- and allenylstannanes during the catalytic process.
Highly enantioselective synthesis of alky- and aryl-substituted α-allenic alcohols
作者:Shekhar V. Kulkarni、Herbert C. Brown
DOI:10.1016/0040-4039(96)00821-0
日期:1996.6
orane and warming to room temperature gives exclusively the propargylic diisopinocampheylboron derivatives. These on treatment with aldehydes at −100 °C in ether, provide alkyl- and aryl-substitutedα-allenicalcohols in high regiomeric and enantiomeric purities.