Asymmetric methylation and phenylation of the chiral pyridinium salt 7, as well as methylation of chiral pyridinium salt 18, with Grignard reagents occurred in good yield and with good-to-excellent diastereoselectivities (Schemes 2 and 3, resp.). These results are best explained by assuming chelate control to govern the asymmetric alkylation/arylation process. The minimum-energy conformations of the
Asymmetric Synthesis of 2-Alkyl(Aryl)-2,3-dihydro-4-pyridones by Addition of Grignard Reagents to Chiral 1-Acyl-4-methoxypyridinium Salts
作者:Daniel L. Comins、Sajan P. Joseph、R. Richard Goehring
DOI:10.1021/ja00090a019
日期:1994.6
Grignard addition to a chiral 1-acyl-4-methoxypyridinium salt provides synthetically useful 2-alkyl(aryl)-2,3-dihydro-4-pyridones in high diastereomeric excess
Generation and Regioselective Trapping of a 3,4-Piperidyne for the Synthesis of Functionalized Heterocycles
作者:Travis C. McMahon、Jose M. Medina、Yun-Fang Yang、Bryan J. Simmons、K. N. Houk、Neil K. Garg
DOI:10.1021/jacs.5b01589
日期:2015.4.1
We report the generation of the first 3,4-piperidyne and its use as a building block for the synthesis of annulated piperidines. Experimental and computational studies of this intermediate are disclosed, along with comparisons to the well-known 3,4-pyridyne. The distortion/interaction model is used to explain the observed regioselectivities.
Stereoselective addition of (triphenylsilyl)magnesium bromide to chiral 1-acyl-4-methoxypyridinium salts. Synthesis and reactions of enantiopure 1-acyl-2-(triphenylsilyl)-2,3-dihydro-4-pyridones
作者:Daniel L. Comins、Michael O. Killpack
DOI:10.1021/ja00053a050
日期:1992.12
Comins, Daniel L.; Killpack, Michael O.; Despagnet, Emilie, Heterocycles, 2002, vol. 58, p. 505 - 519
作者:Comins, Daniel L.、Killpack, Michael O.、Despagnet, Emilie、Zeller, Emmanuel