Gold-Catalyzed Benzannulation of Electronically Rich/Rich and Deficient/Deficient Oxoalkynes with Alkynes
作者:Tarun Sarkar、Biswajit Panda
DOI:10.1055/s-0032-1318454
日期:——
Two different strategies have been developed to perform the gold-catalyzed benzannulation of both electron-rich pyridine containing oxoalkynes with electron-rich alkynes as well as electron-deficient pyridine containing oxoalkynes with electron-deficient alkynes. The benzannulation between electron-rich oxoalkynes with electron-rich alkynes proceeds in the presence of highly electron-deficient gold catalysts, whereas using catalytic amount of alcohol benzannulation was performed efficiently between electron-deficient oxoalkynes with electron-deficient alkynes.
Gold and Palladium Combined for the Sonogashira Coupling of Aryl and Heteroaryl Halides
作者:Tarun Sarkar、Biswajit Panda
DOI:10.1055/s-0032-1318119
日期:——
transmetalation step. A highly efficient gold and palladium combined methodology for the Sonogashiracoupling of a wide array of electronically and structurally diverse aryl and heteroaryl halides is described. The orthogonal reactivity of the two metals shows high selectivity and extreme functional group tolerance in Sonogashiracoupling. A brief mechanistic study reveals that the gold acetylide intermediate enters
An Approach to Highly Functionalized Quinolines and Isoquinolines via a Gold-Catalyzed Benzannulation
作者:Tarun Sarkar、Biswajit Panda、Jhuma Bhadra
DOI:10.1055/s-0030-1259555
日期:2011.3
The AuCl 3 -catalyzed benzannulation of pyridine-containing oxo-alkynes with external as well as internal alkynes proceeds under mild conditions, and a variety of quinoline and isoquinoline derivatives are produced in good to excellent yields. The reaction proceeds through the formation of aza-isobenzopyrylium auric ate complexes as evident from trapping experiments.