A chemoselective Reformatsky–Negishi approach to α-haloaryl esters
摘要:
A practical synthesis of alpha-haloaryl esters has been achieved via a chemoselective Negishi coupling of poly-halogenated aromatics and Reformatsky reagents in the presence of catalytic Pd(dba)(2) and Xantphos. This chemistry tolerates a variety of aryl halides and was successfully applied to the synthesis of Ibuprofen. The alpha-haloaryl ester products, exemplified by ethyl 2-(4-bromo-2-chlorophenyl)acetate (3a), can be further functionalized via palladium or copper catalysis to afford an array of a-aryl esters. (C) 2014 Elsevier Ltd. All rights reserved.
A versatile and site-selective rhodium(III)-catalyzed aerobic oxidativealkenylation of arylacetamides including primary, secondary, and tertiary amides having a weak O-coordinating acetamide directing group with alkenes is described. In the reaction, air was utilized as a sole oxidant. The reaction was compatible with activated alkenes and maleimides.
The C–H alkylation of arylacetamides with activated alkenes such as substituted acrylates and vinylsulphone in the presence of a ruthenium catalyst and organic acid via the weak O-coordination under the redox free version is described. The present protocol was effective with different substituted arylacetamides including secondary and tertiary amides. The reaction mechanism including the ortho C–H
reductive functionalization of amides to afford 5‐amino substituted 4,5‐dihydroisoxazoles is presented. The reduction of amides generates reactive enamines, which upon the addition of hydroximinoyl chlorides and base undergoes a 1,3‐dipolar cycloaddition reaction that gives access to the desired heterocyclic compounds. The transformation of amides is highly chemoselective and tolerates functional groups
The development of an efficient protocol for the reductivefunctionalization of amides into pyrimidinediones and amino-substituted thioacrylamides is presented. Enamines are generated in a highly chemoselective amide hydrosilylation reaction catalyzed by molybdenum hexacarbonyl in combination with 1,1,3,3-tetramethyldisiloxane. The direct addition of either isocyanate or isothiocyanate generates the
Rhodium(III)-Catalyzed Redox-Neutral Weak <i>O</i>-Coordinating Vinylation and Allylation of Arylacetamides with Allylic Acetates
作者:Subramanian Jambu、Masilamani Jeganmohan
DOI:10.1021/acs.orglett.9b01995
日期:2019.7.19
efficient Rh(III)-catalyzed redox-neutral weak O-coordinating vinylation and allylation of arylacetamides with allylic acetates are described. A wide variety of arylacetamides containing primary, secondary, and tertiary amides and substituted allylic acetates was compatible for the reaction. The synthesized ortho-vinylated arylacetamides were converted into ortho-vinylated phenyl aceticacid and biologically