Mitsunobu Approach to the Synthesis of Optically Active α,α-Disubstituted Amino Acids
作者:Jonathan E. Green、David M. Bender、Stona Jackson、Martin J. O’Donnell、James R. McCarthy
DOI:10.1021/ol802325h
日期:2009.2.19
α-azido esters by Mitsunobureaction with HN3. Optimization of this reaction was shown to proceed at room temperature with high chemical yield using 1,1-(azodicarbonyl)dipiperidine (ADDP) and trimethylphosphine (PMe3). Complete inversion of configuration was observed at the α-carbon. Several α,α-disubstituted amino acids were synthesized in high overall chemical yield and optical purity.
Isothiourea‐Catalyzed Acylative Kinetic Resolution of Tertiary α‐Hydroxy Esters
作者:Shen Qu、Samuel M. Smith、Víctor Laina‐Martín、Rifahath M. Neyyappadath、Mark D. Greenhalgh、Andrew D. Smith
DOI:10.1002/anie.202004354
日期:2020.9.14
acylative kinetic resolution (KR) of acyclic tertiary alcohols has been developed. Selectivity factors of up to 200 were achieved for the KR of tertiary alcohols bearing an adjacent ester substituent, with both reaction conversion and enantioselectivity found to be sensitive to the steric and electronic environment at the stereogenic tertiarycarbinol centre. For more sterically congested alcohols