1421924-64-2Relevant academic research and scientific papers
Stereodivergent Synthesis of α,α-Disubstituted α-Amino Acids via Synergistic Cu/Ir Catalysis
Wei, Liang,Zhu, Qiao,Xu, Shi-Ming,Chang, Xin,Wang, Chun-Jiang
, p. 1508 - 1513 (2018)
Cu/Ir dual catalysis has been developed for the stereodivergent α-allylation of aldimine esters. The method enables the preparation of a series of nonproteinogenic α-amino acids (α-AAs) bearing two contiguous stereogenic centers in high yield with excellent stereoselectivity. All four product stereoisomers could be obtained from the same set of starting materials via pairwise combination of two chiral catalysts. Notably, one-pot protocol could be successfully applied for the preparation of the bimetallic Cu/Ir complexes to simplify the manipulation of Cu/Ir dual catalysis. This method could be further utilized for the construction of the key intermediate of a bioactive pyrrolidine derivative and the concise synthesis of a plant growth regulator (2S,3S)-2-amino-3-cyclopropylbutanoic acid.
Control of diastereoselectivity for iridium-catalyzed allylation of a prochiral nucleophile with a phosphate counterion
Chen, Wenyong,Hartwig, John F.
, p. 2068 - 2071 (2013/04/10)
We report a highly diastereo- and enantioselective allylation of azlactones catalyzed by the combination of a metallacyclic iridium complex and an optically inactive phosphate anion. The process demonstrates an approach for conducting diastereoselective reactions with prochiral nucleophiles in the presence of metallacyclic allyliridium complexes. The reaction provides access to an array of enantioenriched allylated azlactones containing adjacent tertiary and quaternary carbon centers. Preliminary mechanistic studies suggest that the phosphate and methyl carbonate anions together induce the unusually high diastereoselectivity.
