Rh<sup>III</sup>-Catalyzed Regioselective Preparation of 3-Hetero-Substituted Isocoumarins from Aryl Carboxylic Acids and Alkynes
作者:Lijuan Song、Jing Xiao、Wanrong Dong、Zhihong Peng、Delie An
DOI:10.1002/ejoc.201601330
日期:2017.1.10
An oxygen-mediated annulation reaction has been reported herein. Various 3-hetero-substituted isocoumarins were successfully prepared with high efficiency (yields up to 88 %) and good functional-group tolerance (35 examples) in the presence of a rhodium catalyst. A plausible mechanism has also been proposed that shows the high regioselectivity mostly likely originates from the electron-density difference
Mukaiyama reagent-promoted metal-free preparation of alkynyl sulfones and phosphonates under mild conditions
作者:Danyang Qi、Wanrong Dong、Zhihong Peng、Yingjun Zhang、Delie An
DOI:10.1016/j.tet.2019.06.035
日期:2019.8
An efficient and mild route for the formation sulfur or phosphor-substituted alkynes was herein demonstrated. The Mukaiyama reagent-mediated transformation started from easily-accessible substrates without carbon-carbon triple bonds, and the reaction proceeded undermildconditions (room temperature) in a one-pot manner, requiring for no transition metal-catalysts. The practical protocol featured for
Bromodecarboxylation of (<i>E</i>)-3-Aryl-2-(diethoxyphosphoryl)acrylic Acids: A Facile Route to Diethyl Arylethynylphosphonates
作者:Henryk Krawczyk、Łukasz Albrecht
DOI:10.1055/s-2007-966057
日期:2007.6
Bromodecarboxylation of (E)-3-aryl-2-(diethoxyphosphoryl)acrylic acids leading to diethyl (Z)-2-aryl-1-bromovinylphosphonates has been conducted for the first time. The products have been shown to be useful for the synthesis of diethyl arylethynylphosphonates.
A new simple method for the synthesis of 1-alkynylphosphonates using (EtO)2P(O)CCl3 as precursor
作者:Rachel Dizière、Philippe Savignac
DOI:10.1016/0040-4039(96)00131-1
日期:1996.3
1-Alkynylphosphonates 4 were obtained from (EtO)2P(O)CCl31 and aldehydes in a one-pot procedure. It involves the formation of α-chlorovinyl phosphonate intermediates 3 by a Peterson olefination reaction followed by dehydrochlorination with LiHMDS.
A Highly Reactive Dicationic Iridium(III) Catalyst for the Polarized Nazarov Cyclization Reaction
作者:Tulaza Vaidya、Abdurrahman C. Atesin、Ildiko R. Herrick、Alison J. Frontier、Richard Eisenberg
DOI:10.1002/anie.201000100
日期:2010.4.26
Pushing the Nazarov envelope: An electrophilic complex (1; see scheme; EDG=electron‐donating group, EWG=electron‐withdrawing group, binap=2,2‐bis(diphenylphosphanyl)‐1,1‐binaphthyl) exhibits unusual catalytic activity in the polarizedNazarovcyclizationreaction. Aryl vinyl ketones that show poor reactivity with well‐known catalysts can be readily cyclized with 1/AgSbF6 (1:1) under mild reaction conditions