Stereoselective Double Friedel−Crafts Alkylation of Indoles with Divinyl Ketones
作者:Andrew C. Silvanus、Stephen J. Heffernan、David J. Liptrot、Gabriele Kociok-Köhn、Benjamin I. Andrews、David R. Carbery
DOI:10.1021/ol900014a
日期:2009.3.5
A tandem double Friedel−Crafts reaction of indoles and nonsymmetrical divinyl ketones has been achieved. The tandem reaction forms complex [6-5-7]-tricyclic indoles in excellent yields. The reaction is completely regioselective and offers high levels of syn diastereoselectivity. The reaction is also seen to be sensitive to substrate structure and catalyst.
Enantioselective Addition of Remote Alkyl Radicals to Double Bonds by Photocatalytic Proton-Coupled Electron Transfer (PCET) Deconstruction of Unstrained Cycloalkanols
ring opening of unstrained cycloalkanols by a proton-coupled electrontransfer (PCET) process, to 2-acyl imidazoles previously coordinated to a rhodium-based chiral Lewis acid. High yields and enantioselectivites up to 99% are achieved in 1 h. Mechanistic investigations support the formation of the remote alkyl radical by a PCET process, and theoretical studies explain the observed stereochemistry