Enantioselective synthesis of threo-α,β-dihydroxyphosphonates by asymmetric dihydroxylation of 1(E)-alkenylphosphonates with AD-mix reagents
摘要:
Asymmetric dihydroxylation (AD) of 1(E)-alkenylphosphonates with an AD-mix -alpha or -beta reagent was examined to give a series of optically active threo-alpha,beta-dihydroxyphosphonates. Good enantioselectivity (>88% eel was observed in the AD reaction of 1(E)-alkenylphosphonates with conjugated aromatic substituents. The steric effects of the ester functionality in the course of the dihydroxylation were also evaluated. Enantioselectivity and yield were significantly improved when the AD reaction was carried out with dimethyl phosphonate instead of diethyl phosphonate. (C) 1997 Elsevier Science Ltd. All rights reserved.
Copper-Catalyzed Microwave-Expedited Oxyphosphorylation of Alkynes with Diethyl Phosphite and <i>t</i>-Butyl Hydroperoxide Synthesis of Densely Functionalized Phosphonylated Indenones
作者:Pablo Macías-Benítez、Alfonso Sierra-Padilla、Manuel J. Tenorio、F. Javier Moreno-Dorado、Francisco M. Guerra
DOI:10.1021/acs.joc.1c01763
日期:2021.12.3
Treatment of alkynes with diethylphosphite and t-butyl hydroperoxide in the presence of [Cu(MeCN)4]BF4 under microwave irradiation produced the oxyphosphorylation of the triple bond, giving rise to the corresponding β-ketophosphonates in moderate-to-good yields. When the triple bond was conjugated to a carbonyl group bearing an aromatic ring, it led to the cyclization of the resulting ketone intermediate