Selective ene-yne coupling-functionalization: A new strategy in constructing heterocycles
作者:Zhong Wang、Xiyan Lu
DOI:10.1016/0040-4020(95)00035-7
日期:1995.2
Fluorinated derivatives of 3-alkylidene-2(3H)-dihydrofuranone have been synthesized by sodium dithionite initiated tandem perfluoroalkylation-cyclization of allylic 2-alkynoates in fair to good yield and high stereoselectivity. Fluorinated 3-alkylidene-2(3H)-pyrrolidone derivatives were prepared similarly. A mechanistic rationale concerning the different radical steps and the differences between esters
Structural factors affecting the selectivities in the palladium (II) catalyzed cyclization of N-alkenyl-2-alkynamides
作者:Huanfeng Jiang、Shengming Ma、Guoxin Zhu、Xiyan Lu
DOI:10.1016/0040-4020(96)00648-5
日期:1996.8
Palladiumcatalyzedcyclization of N-alkenyl 2-alkynamides occurred smoothly in the presence of CuCl2 and LiCl affording α-chloroalkylidene-γ-butyrolactams and α-chloroalkylidene-δ-valerolactams valerolactams stereoselectively. The regioselectivity of the intramolecular C-C double bond insertion was influenced by the substituent group on the substrate. When an alkyl group was introduced into the 1'-position