here a palladium(II)-catalyzed oxidative cyclization reaction of N-allylimines derived from methyl ketones, typically acetophenones, affording pyrrole derivatives at room temperature under oxygen atmosphere. The reaction likely proceeds through α-palladation of the imine followed by olefin migratory insertion and β-hydride elimination, thus representing a new example of aerobicdehydrogenative Heck cyclization
Carbon−Carbon Bond Formation and Pyrrole Synthesis via the [3,3] Sigmatropic Rearrangement of <i>O</i>-Vinyl Oxime Ethers
作者:Heng-Yen Wang、Daniel S. Mueller、Rachna M. Sachwani、Hannah N. Londino、Laura L. Anderson
DOI:10.1021/ol100659q
日期:2010.5.21
A new method for the synthesis of 2,4- and 2,3,4-substituted pyrroles in two or three steps from commercially available ketones and allyl hydroxylamine is described. An iridium-catalyzed isomerization reaction has been developed to convert O-allyl oximes to O-vinyl oximes, which undergo a facile [3,3] rearrangement to form 1,4-imino aldehyde Paal−Knorr intermediates that cyclize to afford the corresponding
Palladium-catalysed aerobic oxidative Heck-type alkenylation of Csp3–H for pyrrole synthesis
作者:Lingkui Meng、Kun Wu、Chao Liu、Aiwen Lei
DOI:10.1039/c3cc42307g
日期:——
The first palladium-catalysed aerobic oxidative intramolecular alkenylation of Csp(3)-H bonds was described. The reaction conditions were mild and molecular oxygen was used as the terminal oxidant. Kinetic studies showed that the Csp(3)-H metallation step was a slow step.