Kinetic Resolution of 2-Substituted 2,3-Dihydro-4-pyridones by Palladium-Catalyzed Asymmetric Allylic Alkylation: Catalytic Asymmetric Total Synthesis of Indolizidine (−)-209I
allylic substitution reaction using a commercially available (S)-P-Phos as a ligand, affording optically active dihydropyridones and C-allylated dihydropyridones in high yields and good enantioselectivities with the S-factor up to 43. With this protocol, a catalyticasymmetric total synthesis of indolizidine (−)-209I was realized for the first time.
Enantioselective Catalytic Dearomative Addition of Grignard Reagents to 4-Methoxypyridinium Ions
作者:Yafei Guo、Marta Castiñeira Reis、Johanan Kootstra、Syuzanna R. Harutyunyan
DOI:10.1021/acscatal.1c01544
日期:2021.7.16
We describe a general catalytic methodology for the enantioselective dearomative alkylation of pyridine derivatives with Grignard reagents, allowing direct access to nearly enantiopure chiral dihydro-4-pyridones with yields up to 98%. The methodology involves dearomatization of in situ-formed N-acylpyridinium salts, employing alkyl organomagnesium reagents as nucleophiles and a chiral copper (I) complex