Palladium-Catalyzed Decarboxylative Carbonylative Transformation of Benzyl Aryl Carbonates: Direct Synthesis of Aryl 2-Arylacetates
作者:Jian-Xing Xu、Xiao-Feng Wu
DOI:10.1021/acs.orglett.8b02631
日期:2018.9.21
A procedure on palladium-catalyzed decarboxylative alkoxycarbonylation of carbonates for the synthesis of aryl 2-arylacetates has been developed. A broad range of aryl 2-arylacetates were obtained in good yields under mild conditions under a carbon monoxide atmosphere. Interestingly, other alcohols can be added as nucleophiles as well, and the corresponding esters were also obtained in good yields
Heteroaromatic esters were found to be applicable as an arylating agent for the Pd-catalyzed α-arylation of ketones in a decarbonylative fashion. The use of our in-house ligand, dcypt, enabled this unique bond formation. Considering the ubiquity and low cost of aromatic esters, the present work will allow for rapid access to valuable α-aryl carbonyl compounds.
unsymmetrical sulfides from esters and thiols in the presence of InI3 and either 1,1,3,3-tetramethyldisiloxane (TMDS) or PhSiH3 as the reductant was developed. This protocol was applied to not only benzoic acid esters that have a methoxy, methyl, chloro, bromo, iodo, or trifluoromethyl group on the aromatic ring but also aliphatic acid esters with either aromatic or aliphatic thiols. A reaction mechanism
New methods and reagents in organic synthesis. 17. Trimethylsilyldiazomethane(TMSCHN2) as a stable and safe substitute for hazardous diazomethane. Its application to the arndt-eistert synthesis.
作者:TOYOHIKO AOYAMA、TAKAYUKI SHIOIRI
DOI:10.1248/cpb.29.3249
日期:——
Although diazomethane is used in the Arndt-Eistert synthesis, it is both highly toxic and also explosive, and hence should be very carefully handled. In place of this hazardous diazomethane, stable and safe trimethylsilyldiazomethane (TMSCHN2) was found to be very useful for the Arndt-Eistert synthesis. TMSCHN2 was easily acylated with a carboxylic acid chloride in tetrahydrofuran-acetonitrile, and thermal treatment of the acylated product in benzyl alcohol and 2, 4, 6-trimethylpyridine smoothly gave the benzyl ester of a homologated acid. Nucleophiles other than benzyl alcohol could also be used. TMSCHN2 may also be able to replace diazomethane in other areas of chemistry.
Functional Group Interconversion: Decarbonylative Borylation of Esters for the Synthesis of Organoboronates
作者:Lin Guo、Magnus Rueping
DOI:10.1002/chem.201604504
日期:2016.11.14
A new and efficient nickel‐catalyzed decarbonylative borylation reaction of carboxylic acid esters with bis(pinacolato)‐diboron has been developed. This transformation allows access to structurally diverse aryl as well as alkenyl and alkyl boronate esters with high reactivity, broad substrate scope, and excellent functional‐group tolerance. Further experiments show that this protocol can be carried