Convenient synthesis of alkyl (Z)- and (E)-2,3-bis(trimethylstannyl)alk-2-enoates and N,N-dimethyl (E)-2,3-bis(trimethylstannyl)alk-2-enamides
作者:Edward Piers、Renato T. Skerlj
DOI:10.1039/c39860000626
日期:——
Palladium(0)-catalysed addition of (Me3Sn)2 to the α,β-acetylenic esters (1a–n) and amides (4a–d) provides the (Z)-2,3-bis(trimethylstannyl)alk-2-enoates (2a–n) and the (E)-2,3-bis(trimethylstannyl)alk-2-enamides (6a–d), respectively; thermolysis of (2a–h) transforms these substances into the corresponding (E)-isomers (3a–h).
Reactions of some alkynyl halides with Samarium(II) iodide
作者:Zhihong Zhou、Denis Larouche、Sharon M. Bennett
DOI:10.1016/0040-4020(95)00703-b
日期:1995.10
Certain alkynyl halides (6-halo-1-ynes) react with samarium(II) iodide (SmI2) to give cyclized products (methylenecyclopentanes) in good yield. We have found some interesting evidence for the presence of radical and unstable organosamarium intermediates in these reductive cyclizations. Methyl 7-halohept-2-ynoates are not. however, good substrates for this cyclization methodology.