New Synthesis of ketene thioacetals, vinylsulfides and their seleno analogues
作者:J.N. Denis、A. Krief
DOI:10.1016/s0040-4039(00)87628-5
日期:1982.1
Title compounds have been prepared on reaction of thioacetals, orthothioesters and their seleno analogues with diphosphorus tetraiodide (P2I4) or phosphorus triiodide (PI3).
A new and generalsynthesis of ketene S,S-thioacetals (1) and ketene O.S-thioacetals (6) which involves the Horner-Wittig reaction of carbonyl compounds with the metallated S,S- and O,S-thioacetals of formyl-phosphonates (4 and 5) is described. The Horner-Wittig reaction of 4 with aromatic aldehydes can be carried out under two-phase conditions. The generation of the carbanions from 4 and 5 as well
烯酮S,S-硫缩醛(1)和烯酮OS-硫缩醛(6)的新的合成方法,涉及羰基化合物与甲酰基膦酸酯的金属化S,S-和O,S-硫缩醛的Horner-Wittig反应(4和5)被描述。4与芳族醛的霍纳-维蒂希反应可以在两相条件下进行。通过低温31 P NMR光谱研究了4和5中碳负离子的生成以及它们与羰基化合物的反应过程。已发现,甲酰基膦酸酯的S,S-硫缩醛(4)与甲膦酸酯的O,S-硫缩醛(5)相比非常容易金属化。)仅在用叔丁基锂处理时才能形成锂衍生物。从31 P NMR光谱中未获得证据支持形成甲酰基膦酸酯的0-0-缩醛的锂衍生物(12)。
The use of phosphonodithioformates for the synthesis of ketene dithioacetals
作者:Andrew Bulpin、Serge Masson、Aboubacary Sene
DOI:10.1016/s0040-4039(00)99259-1
日期:1989.1
Phosphonodithioformates 1 undergo thiophilic addition with both organolithium and Grignard reagents to give metallated dithioacetals of formyl-phosphonates 2, available for protonation, alkylation or use in Wittig-Horner reactions. Oxidation of 1 by meta-chloroperbenzoic acid leads to the corresponding sulphine 4 equally suitable for thiophilic addition.
Stereoconservative Formation and Reactivity of α-Chalcogen-Functionalized Vinyllithium Compounds from α-Bromo-vinylic Chalcogenides
作者:Antonio Braga、Gilson Zeni、Leandro de Andrade、Claudio Silveira
DOI:10.1055/s-1997-3227
日期:1997.5
Bromine/lithium exchange was performed upon treatment of α-bromo-vinylic chalcogenides with butyllithium in hexane at room temperature to provide α-chalcogen-vinyllithium intermediates quantitatively. Addition of electrophiles to the lithiated compounds gave the corresponding functionalized vinylic chalcogenides in good yields with retention of configuration.
p-tolylsulfones, easily prepared frombase-catalyzed condensation of aromatic aldehydes with a variety of p-tolylsulfones, were efficiently transformed to the corresponding (E)-β-substituted aromatic olefins in a stereoselective manner through Mg-promoted reduction. The reaction may be initiated through electron transfer from Mg metal to the vinyl sulfones to give the corresponding anionic species