Allenyl organometallic reagents of type R2C = C = CH(CH2)nCH2M undergo cyclization at the central allenic carbon for n = 2 (M = Li) and at the near allenic carbon for n = 3 (M = CuCNLi) to provide cyclopentane systems; little cyclization was observed for the n = 4 systems (M = Li, CuCNLi).
Nucleophilic reactions of propargyl acetates mediated by titanocene dichloride and magnesium
作者:Fanglong Yang、Gang Zhao、Yu Ding
DOI:10.1016/s0040-4039(01)00309-4
日期:2001.4
Reaction of Cp2TiCl2/Mg with propargyl acetates form allenyl titanium intermediates, which undergo nucleophilic addition reactions to aldehydes or ketones to give homopropargyl alcohols in high yields. Subsequent nucleophilic addition to acetonitrile and nucleophilic substitution with allyl bromide are also mentioned.