Electrochemical allylation of aldehydes and ketones with allylic alcohols
作者:Jiatai Zhang、Lanlan Zhang、Wei Xie、Meng Chen、Chao Zhang、Yali Qin、Jianyou Zhao、Fan Wang、Zhong-Quan Liu
DOI:10.1039/d4gc01838a
日期:——
electrochemical allylation of unactivated aldehydes and ketones with allylic alcohols. A wide variety of homoallylic alcohols can be obtained by treatment of aldehydes/ketones with allylalcohols in a simple undivided cell at room temperature. In contrast to previous strategies usingallyl organometallic reagents, allylsilicon, allylboron and allyl halides as the allylic precursors, the present method used allyl
An unprecedented chelation approach to activate C(sp)3-S bonds in nickel-catalyzed cross-coupling reactions is described. Our theme was based on the formation of a chelation complex which results in the enhancement of the reactivity of aliphatic carbon-sulfur bonds. When two dithioacetal functionalities are located in close proximity, selective olefination of one of these two dithioacetal groups can thus be achieved conveniently. Depending on the relative positions of the newly formed double bond and the remaining dithioacetal group, tandem olefination occurs to give the corresponding 1,5-bis-silyl-substituted pentadienes. Various neighboring heteroatom substituents (OR, OH, NR(2) as well as SR groups) can facilitate the olefination of a dithioacetal group. Poly(thioether) linkage afforded the corresponding degradation products via a B-sulfur elimination process. 1,3-Dimercapto- and 1,3-dithiolatopropanes furnish the cyclopropane formation under nickel-catalyzed reaction conditions. The reaction of a dihydrothiopyran with MeMgI in the presence of the nickel catalyst proceeds via a sulfur-coordinated ir-allyl complex, which can further activate the CS bond to give vinylcyclopropane.
SANO, HIROSHI;OKAWARA, MAKOTO;UENO, YOSHIO, SYNTHESIS, BRD, 1984, N 11, 933-935