Palladium-Induced Intramolecular Coupling Reactions of Some Alkenyl(o-iodobenzyl)silanes
摘要:
The first examples for the formation of siloles by intramolecular Heck-type cyclizations are reported. Upon treatment wi th [PdCl2 (PPh3)], the (o-iodobenzyl)vinylsilanes 4a and 4c give the siloles 5a and 5c as well as the vinyl-transfer products 6a and 6c (Scheme 2), respectively. Under CO pressure 4a and 4c react to the carbonylation products in modest yields (Scheme 3). In addition, carbonylative crossover is observed with 4a.
Radical-Induced Formation of Some Siloles and Diazasiloles
作者:Bangwei Ding、Zhu Teng、Reinhart Keese
DOI:10.1021/jo0202684
日期:2002.12.1
reaction of o-iodobenzylvinylsilanes and o-iodoallylsilanes leads to cyclic products in yields of 40-60%. These regioselective cyclizations occur with high preference for a 5-exo and a 7-endo mode with a 6-exo mode being absent. An example for ringclosure via a 7-exo mode is described.
The first examples for the formation of siloles by intramolecular Heck-type cyclizations are reported. Upon treatment wi th [PdCl2 (PPh3)], the (o-iodobenzyl)vinylsilanes 4a and 4c give the siloles 5a and 5c as well as the vinyl-transfer products 6a and 6c (Scheme 2), respectively. Under CO pressure 4a and 4c react to the carbonylation products in modest yields (Scheme 3). In addition, carbonylative crossover is observed with 4a.