10006-90-3Relevant articles and documents
A Cooperative Hydrogen Bond Donor–Br?nsted Acid System for the Enantioselective Synthesis of Tetrahydropyrans
Maskeri, Mark A.,O'Connor, Matthew J.,Jaworski, Ashley A.,Davies, Anna V.,Scheidt, Karl A.
, p. 17225 - 17229 (2018)
Carbocations stabilized by adjacent oxygen atoms are useful reactive intermediates involved in fundamental chemical transformations. These oxocarbenium ions typically lack sufficient electron density to engage established chiral Br?nsted or Lewis acid catalysts, presenting a major challenge to their widespread application in asymmetric catalysis. Leading methods for selectivity operate primarily through electrostatic pairing between the oxocarbenium ion and a chiral counterion. A general approach to new enantioselective transformations of oxocarbenium ions requires novel strategies that address the weak binding capabilities of these intermediates. We demonstrate herein a novel cooperative catalysis system for selective reactions with oxocarbenium ions. This new strategy has been applied to a highly selective and rapid oxa-Pictet–Spengler reaction and highlights a powerful combination of an achiral hydrogen bond donor with a chiral Br?nsted acid.
Studies in the Synthesis of Brevianamides A and B: Pilot Investigations and the Preparation of 1,1-Dimethyl-1,2,4,9-tetrahydrocarbazol-3-one
Ritchie, Robert,Saxton, J. Edwin
, p. 528 - 545 (2007/10/02)
In preliminary investigations directed ultimately at the synthesis of the indoxyl mould metabolites, brevianamides A and B, routes to the synthesis of 4,4-dimethyl-1,3,4,9-tetrahydrocarbazol-2-one and 1,1-dimethyl-1,2,4,9-tetrahydrocarbazol-3-one have bee