作者:Alistair J. M. Farley、Christopher Sandford、Darren J. Dixon
DOI:10.1021/jacs.5b10226
日期:2015.12.30
The highly enantioselective sulfa-Michael addition of alkyl thiols to unactivated α-substituted acrylate esters catalyzed by a bifunctional iminophosphorane organocatalyst under mild conditions is described. The strong Brønsted basicity of the iminophosphorane moiety of the catalyst provides the necessary activation of the alkyl thiol pro-nucleophile, while the two tert-leucine residues flanking a
Structural optimization of thiourea-based bifunctional organocatalysts for the highly enantioselective dynamic kinetic resolution of azlactones
作者:Albrecht Berkessel、Santanu Mukherjee、Thomas N. Müller、Felix Cleemann、Katrin Roland、Marc Brandenburg、Jörg-M. Neudörfl、Johann Lex
DOI:10.1039/b607574f
日期:——
describes the synthesis of a library of structurally diverse bifunctionalorganocatalysts bearing both a quasi-Lewis acidic (thio)urea moiety and a Bronsted basic tertiary amine group. Sequential modification of the modular catalyst structure and subsequent screening of the compounds in the alcoholytic dynamickineticresolution (DKR) of azlactones revealed valuable structure-activity relationships. In particular