Boron-catalyzed dehydrative allylation of 1,3-diketones and β-ketone esters with 1,3-diarylallyl alcohols in water
作者:Guo-Min Zhang、Hua Zhang、Bei Wang、Ji-Yu Wang
DOI:10.1039/d1ra01922h
日期:——
environment friendly was developed. Allylic alcohols could be directly dehydrated in water by B(C6F5)3, without using any base additives. The reaction can afford the corresponding monoallylated product in moderate to high yield and has been performed on a gram-scale, and a quaternarycarboncenter can be constructed for the active methine compounds of 1,3-diketones or β-ketone esters in this process. The product
开发了一种原子经济、绿色环保的无金属催化烯丙基化反应。烯丙醇可以直接在水中通过B(C 6 F 5 ) 3脱水,无需使用任何碱性添加剂。该反应能够以中等到高产率得到相应的单烯丙基化产物,并且已经在克级进行,并且在此过程中可以为1,3-二酮或β-酮酯的活性次甲基化合物构建季碳中心。产物可进一步转化,如合成四取代吡唑类化合物,或1,4-二烯和功能化二氢吡喃。
Hafner,K.; Goliasch,K., Angewandte Chemie, 1962, vol. 74, p. 118
作者:Hafner,K.、Goliasch,K.
DOI:——
日期:——
Hesse,G.; Thieme,P., Justus Liebigs Annalen der Chemie, 1965, vol. 686, p. 64 - 76
作者:Hesse,G.、Thieme,P.
DOI:——
日期:——
Lithium amidoborane, a highly chemoselective reagent for the reduction of α,β-unsaturated ketones to allylic alcohols
Lithium amidoborane (LiNH2BH3, LiAB for short), is capable of chemoselectively reducing α,β-unsaturatedketones to the corresponding allylicalcohols at ambient temperature. A mechanistic study shows that the reduction is via a double hydrogen transfer process. The protic H(N) and hydridic H(B) in amidoborane add to the O and C sites of the carbonyl group, respectively.
alcohols and polyenyl alkylethers catalyzed by TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) under metal-free conditions is presented. Two reaction pathways have been observed. For dienyl alcohols, the reaction proceeds by a [1,3]-proton shift to give γ,δ-unsaturated ketones exclusively. On the other hand, the reaction with polyenyl alkylethers gives the corresponding conjugated vinylethers in good yields