INTERMEDIATES OF SITAGLIPTIN AND PREPARATION PROCESS THEREOF
申请人:Pan Xianhua
公开号:US20130281695A1
公开(公告)日:2013-10-24
Disclosed are intermediates of Sitagliptin, a preparation process thereof, and a process for synthesizing Sitagliptin using these intermediates. Sitagliptin is synthesized by using chiral amino compounds as a raw material, without having to build a chiral center with a chiral asymmetric catalytic hydrogenation, and high-pressure hydrogenation is avoided.
The decarboxylative reduction of naturally abundant carboxylicacids such as α-amino acids and α-hydroxy acids has been achieved via visible-lightphotoredoxcatalysis. By using an organocatalytic photoredox system, this method offers a mild and rapid entry to a variety of high-value compounds including medicinally relevant scaffolds. Regioselective decarboxylation is achieved when differently substituted
photoinduced decarboxylation of methyl aliphaticesters lead to efficient generation of alkyl radicals under mild conditions. The generated alkyl radicals react with a variety of reagents to produce addition, reduction, and substitution products. In addition, the new tin and halogen free process for alkyl radical generation is applicable to a variety of aliphaticesters including those of dipeptides, steroids
Reductive radical decarboxylation of amino-acids and peptides
作者:Derek H. R. Barton、Yolande Hervé、Pierre Potier、Josiane Thierry
DOI:10.1039/c39840001298
日期:——
Radicals generated from N-protected α-amino-acids by photolysis of their N-hydroxypyridine-2-thione esters at room temperature are efficiently quenched by t-butyl thiol to give decarboxy-acids; comparable reactions have been carried out on the side chain carboxy groups of suitably protected aspartic and glutamic acids.