131352-74-4Relevant academic research and scientific papers
N-Heterocyclic Carbene Catalyzed Oxidative Coupling of Alkenes/ α-Bromoacetophenones with Aldehydes: A Facile Entry to α,β-Epoxy Ketones
Reddi, Rambabu N.,Prasad, Pragati K.,Sudalai, Arumugam
, p. 14150 - 14153 (2015)
A novel, N-heterocyclic carbene (NHC) catalyzed direct oxidative coupling of styrenes with aldehydes has been described for the synthesis of α,β-epoxy ketones in good yields. This unprecedented regioselective oxidative coupling employs NBS/DBU/DMSO (DBU=1,8-diazabicyclo [5.4. 0] undec-7-ene, DMSO=dimethylsulfoxide, NBS=N-bromosuccinimide) as an oxidative system at ambient conditions. Additionally, first NHC-catalyzed Darzens reaction of α-bromoketones and aldehydes under mild reaction conditions has also been described. Interestingly, mechanistic studies have revealed the preferred reactivity of NHC with alkene/α-bromoketone rather than aldehydes, thus proceeding via the ketodeoxy Breslow intermediate.
The Benzoin Condensation Catalysis By Bis(azolin-2-ylidene)s and Bis(azolidin-2-ylidene)s and its Interpretation Within the Context of Nucleophilic Carbene Chemistry
Castells, J.,Lopez-Calahorra, F.,Geijo, F.,Perez-Dolz, R.,Bassedas, M.
, p. 715 - 720 (2007/10/02)
The preparation of bis(thiazolin-2-ylidene)s by pasing a methanol solution of the corresponding thiazolium salt through an ion exchange column (basic form) is reported and the use of these "dimers" as benzoin condensation catalysts is studied.The "dimers" show better catalytic activity than the corresponding thiazolium salt plus base.A general discusssion of the benzoin condensation catalysis within the framework of nucleophilic carbene chemistry is carried out and as a result of it the important role played by the "dimers" is emphasized.Mechanistic suggestions related with this fact are put forward.
