Park, Yohan Lee, Young Ju Hong, Suckchang Kim, Mi-hyun Lee, Myungmo Kim, Taek-Soo Lee, Jae Kyun Jew, Sang-sup Park, Hyeung-geun 2024-01-20T16:00:53Z 2024-01-20T16:00:53Z 2021-09-05 2011-12 1615-4150 https://pubs.kist.re.kr/handle/201004/129759 A new enantioselective alpha-alkylation of alpha-tert-butoxycarbonyllactams for the construction of beta-quaternary chiral pyrrolidine and piperidine core systems is reported. alpha-Alkylations of N-methyl-alpha-tert-butoxycarbonylbutyrolactam and N-diphenylmethyl-alpha-tert-butoxycarbonylvalerolactam under phase-transfer catalytic conditions (solid potassium hydroxide, toluene, -40 degrees C) in the presence of (S,S)-3,4,5-trifluorophenyl-3,3',5,5'-tetrahydro-2,6-bis(3,4,5-trifluorophenyl)-4,4'-spirobi[4H-dinaphth[2,1-c:1',2'-e]azepinium] bromide [(S,S)-NAS Br] (5 mol%) afforded the corresponding alpha-alkyl-alpha-tert-butoxycarbonyllactams in very high chemical (up to 99%) and optical yields (up to 98% ee). Our new catalytic systems provide attractive synthetic methods for pyrrolidine- and piperidine-based alkaloids and chiral intermediates with beta-quaternary carbon centers. English WILEY-V C H VERLAG GMBH AMINO-ACIDS ASYMMETRIC-SYNTHESIS BUTYL ESTER STEREOSELECTIVE SYNTHESIS NUCLEOPHILES LACTAMS Highly Enantioselective Phase-Transfer Catalytic alpha-Alkylation of alpha-tert-Butoxycarbonyllactams: Construction of beta-Quaternary Chiral Pyrrolidine and Piperidine Systems Article 10.1002/adsc.201100542 1 ADVANCED SYNTHESIS & CATALYSIS, v.353, no.18, pp.3313 - 3318 ADVANCED SYNTHESIS & CATALYSIS 353 18 3313 3318 scie scopus 000298332200010 2-s2.0-84255177585 Chemistry, Applied Chemistry, Organic Chemistry Article AMINO-ACIDS ASYMMETRIC-SYNTHESIS BUTYL ESTER STEREOSELECTIVE SYNTHESIS NUCLEOPHILES LACTAMS alpha-tert-butoxycarbonyllactams phase-transfer catalytic alpha-alkylation beta-quaternary chiral piperidines beta-quaternary chiral pyrrolidines