Isothiourea-Mediated Asymmetric O- to C-Carboxyl Transfer of Oxazolyl Carbonates: Structure-Selectivity Profiles and Mechanistic Studies
作者:Caroline Joannesse、Craig P. Johnston、Louis C. Morrill、Philip A. Woods、Madeleine Kieffer、Tobias A. Nigst、Herbert Mayr、Tomas Lebl、Douglas Philp、Ryan A. Bragg、Andrew D. Smith
DOI:10.1002/chem.201102847
日期:2012.2.20
The structural motif within a series of tetrahydropyrimidine‐based isothioureas necessary for generating high asymmetric induction in the asymmetric Steglich rearrangement of oxazolylcarbonates is fully explored, with crossover and dynamic 19F NMR experiments used to develop a mechanistic understanding of this transformation.
充分探索了一系列四氢嘧啶基异硫脲中的结构基序,这些结构对于恶唑碳酸酯的不对称Steglich重排产生高不对称诱导是必要的,并使用交叉和动态19 F NMR实验来发展对该转变的机理理解。
Diastereoselective Ugi reaction of chiral 1,3-aminoalcohols derived from an organocatalytic Mannich reaction
Enantiomerically pure beta-aminoalcohols, produced through an organocatalytic Mannichreaction, were subjected to an Ugi multicomponent reaction under classical or Lewis acid-promoted conditions with diastereoselectivities ranging from moderate to good. This approach represents a step-economical path to enantiomerically pure, polyfunctionalized peptidomimetics endowed with three stereogenic centers