Ru-TsDPEN with formic acid/Hunig's base for asymmetric transfer hydrogenation, a practical synthesis of optically enriched N-propyl pantolactam.
The Noyori-Ikariya catalysts, Ru-TsDPEN 1 or 2, in combination with HCOOH/Hunig's base (5:2) have been successfully utilized for catalytic asymmetric transfer hydrogenation of alpha-ketopantolactam, and optically enriched N-substituted pantolactam was prepared (S/C = 500, up to 95% ee and 99% conversion in HCOOH/Hunig's base condition). More than 2 kg of this key intermediate 9 has been synthesized efficiently with excellent chemical yield and chiral purity.
Zhang
Ji
J
Research API, Pfizer Global Research & Development, Michigan Laboratories, Pfizer Inc., 2800 Plymouth Road, Ann Arbor, Michigan 48105, USA. ji.zhang@bms.com
Blazecka
Peter G
PG
Bruendl
Michelle M
MM
Huang
Yun
Y
D000588:Amines / Q000737:chemistry; D005029:Ethylenediamines / Q000737:chemistry*; D005561:Formates / Q000737:chemistry*; D006865:Hydrogenation; D007769:Lactams / Q000138:chemical synthesis*; D009942:Organometallic Compounds / Q000737:chemistry*
D000588:Amines; D005029:Ethylenediamines; D005561:Formates; D007769:Lactams; D009942:Organometallic Compounds; C520782:ruthenium-(1S,2S)-N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine; C030544:formic acid