Photochemical isomerization of N-monosubstituted .alpha.,.beta.-unsaturated thioamides to iminothietanes
作者:Masami Sakamoto、Tsutomu Ishida、Tsutomu Fujita、Shoji Watanabe
DOI:10.1021/jo00034a040
日期:1992.4
Photochemical isomerization of thiomethacryl-, thiotiglyl-, and thiocrotonamides gives iminothietanes, N-(2-thietanylidene)amines, in good yields. The iminothietanes reverted quantitatively to the starting materials on heating. Use of Michler's ketone or thioxanthone as sensitizers indicates that the photoelectric cyclization proceeds from the triplet excited state. Irradiation of N-benzylthiocinnamamide does not give an iminothietane, but only cis-trans isomerization that reached the photostationary state at cis/trans = 1.7.