Asymmetric dihydroxylation of 1-acyloxy-2(E)-alkenylphosphonates with AD-mix reagents. Effects of 1-acyloxy functional groups on the asymmetric dihydroxylation
摘要:
Asymmetric dihydroxylation (AD) of a racemic mixture of 1-acyloxy-2(E)-alkenylphosphonates with AD-mix-alpha or -beta reagents was examined. The kinetic rate of dihydroxylation was highly dependent upon the configuration of the 1-acyloxy functional group as well as the nature of substituents at the 3-position. ?he reaction of a racemic mixture of diethyl (E)-3-phenyl-1-acetyloxy-2-propenylphosphonate with an AD-mix-beta reagent preferentially dihydroxylated the R-enantiomer to leave an unreacted S-enantiomer of high enantiomeric purity. Double diastereoselection of the resolved diethyl 3-phenyl-1-acetyloxy-2(E)-propenylphosphonate in dihydroxylation was also examined. (C) 1997 Elsevier Science Ltd. All rights reserved.
A green procedure for the regio- and chemoselective hydrophosphonylation of unsaturated systems using CaO under solventless conditions
作者:Elisa Martínez-Castro、Óscar López、Inés Maya、José G. Fernández-Bolaños、Marino Petrini
DOI:10.1039/c0gc00026d
日期:——
Diethyl phosphite and diphenylphosphine add to a series of unsaturated derivatives using environmentally-friendly calcium oxide as a basic promoter under solventless conditions at room temperature. The corresponding adducts are obtained in a totally regioselective fashion, via a 1,4-addition on α,β-unsaturated esters and sulfone, and a 1,2-addition on cyclic and acyclic α,β-unsaturated aldehydes and
Kinetic resolution of hydroxyalkanephosphonates catalyzed by Candida antarctica lipase B in organic media
作者:Yonghui Zhang、Chengye Yuan、Zuyi Li
DOI:10.1016/s0040-4020(02)00229-6
日期:2002.4
A series of hydroxyalkanephosphonates were studied as substrates for CALB catalyzed acetylation with emphasis on enantioselectivity and chemical structure of substrates. Some hydroxyalkanephosphonates could be resolved successfully to give both (R)- and (S)-isomers with high enantiomeric excess.
<i>O</i>-Allylated Pudovik and Passerini Adducts as Versatile Scaffolds for Product Diversification
作者:Mansour Dolé Kerim、Tania Katsina、Martin Cattoen、Nicolas Fincias、Stellios Arseniyadis、Laurent El Kaïm
DOI:10.1021/acs.joc.0c01721
日期:2020.10.2
The palladium-catalyzed O-allylation of α-hydroxyphosphonates and α-hydroxyamides obtained from Pudovik and Passerini multicomponent reactions has allowed interesting and highly straightforward access to a variety of building blocks for product diversification. These post-functionalizations include a selective base- or ruthenium hydride-mediated isomerization/Claisen rearrangement cascade and a ring-closing
Abstract The expedient syntheses of small libraries of ((β-ethoxycarbonyl, -cyano and -acetyl)propyloxy) methylphosphonate scaffolds bearing olefin, sulfanyl, or amine functions are described. All these new derivatives are readily produced from easily available starting reagents (aldehydes, electron-poor olefins, and dialkylphosphites) following a three steps reaction sequence of condensations, SN2′-type
Palladium-catalysed<i>O</i>-Allylation of α-Hydroxyphosphonates: An Expedient Entry into Phosphono-oxaheterocycles
作者:Mansour Dolé Kerim、Martin Cattoen、Nicolas Fincias、Aurélie Dos Santos、Stellios Arseniyadis、Laurent El Kaïm
DOI:10.1002/adsc.201701150
日期:2018.2.1
We report here an unprecedented palladium-catalysed O-allylation of α-hydroxyphosphonates. The method was eventually included in a sequential Pudovik/Tsuji-Trost type O-allylation/Ring-Closing Metathesis to afford a variety of phosphorylated heterocycles of various sizes ranging from 5 to 16 starting from readily available aldehydes.