Rhodium(I)-Catalyzed Coupling–Cyclization of C═O Bonds with α-Diazoketones
作者:Ziyang Chen、Xinwei Hu、Junmin Huang、Wei Zeng
DOI:10.1021/acs.orglett.8b01541
日期:2018.7.6
An unprecedented intermolecular nucleophilic attack of C═X bonds (X = O and S) on the rhodium(I)-carbenes has been developed. This transformation allows for the coupling–cyclization of aroylamides with α-diazoketones and provides concise access to 2,4,5-trisubstituted 1,3-oxazoles and 1,3-thiazoles with a broad tolerance of functional groups.
Efficient synthesis of multi-substituted oxazoles under solvent-free microwave irradiation
作者:Jong Chan Lee、Hyun Jung Choi、Yong Chan Lee
DOI:10.1016/s0040-4039(02)02493-0
日期:2003.1
A new and efficient method for the synthesis of multi-substituted oxazoles from various carbonyl compounds has been developed using sequential treatment of carbonyl compounds with HDNIB and amides such as acetamide or benzamide under solvent-free microwaveirradiation conditions.
A highly efficient method for the synthesis of oxazole derivativesfrom simple amides and ketones has been established via a Pd(II)-catalyzed sp2 C–H activation pathway in one step. The reaction is supposed to proceed through a C–Nbond formation followed by a C–O bond formation closing the ring. Because of the simple and readily available starting materials, easy operation, and high bioactivity of
Generation of Dimethyl Sulfoxide Coordinated Thermally Stable Halogen Cation Pools for C−H Halogenation
作者:Pallaba Ganjan Dalai、Kuntal Palit、Niranjan Panda
DOI:10.1002/adsc.202101291
日期:2022.3
A method to generate halogen cation pools from the reaction of 1,2-dihaloethanes (hal=Br, I) and dimethyl sulfoxide (DMSO) for C−H halogenation of arenes and heteroarenes was reported. The initial reaction of DMSO and 1,2-dihaloethane generates the sulfur ylide, which undergoes pyrolytic elimination of ethylene by affording halonium ions. These ions were accumulated and stabilized by DMSO through coordination
Gold Catalysis: Phenol Synthesis in the Presence of Functional Groups
作者:A. Stephen K. Hashmi、Jan P. Weyrauch、Elzen Kurpejović、Tanja M. Frost、Burkhard Miehlich、Wolfgang Frey、Jan W. Bats
DOI:10.1002/chem.200501268
日期:2006.7.24
acylated hydroxymethyl and ammonium groups, on the furan ring of substrates in gold-catalyzed phenolsynthesis has been investigated. The furan ring was also replaced by different heterocycles, such as pyrroles, thiophenes, oxazoles, and a 2,4-dimethoxyphenyl group; goldcatalysis then delivered no phenols, but occasionally other products were obtained. [Ru(3)(CO)(12)] also catalyzed the conversion