NAD(P)<sup>+</sup>–NAD(P)H Models. 87. Nonsteric Stereochemistry Controlled by a Carbonyl Dipole
作者:Atsuyoshi Ohno、Akihiro Tsutsumi、Norimasa Yamazaki、Mutsuo Okamura、Yuji Mikata、Masayuki Fujii
DOI:10.1246/bcsj.69.1679
日期:1996.6
at room temperature. Upon the reduction of 11-Me-MMPA+ with a pair of diastereomeric dihydropyridine derivatives, the reacting face is always that in which the carbonyl dipole in the cation is included (i.e., syn selectivity), regardless the configuration of the reducing agent. A steric hindrance, in a classical sense, and other factors contribute to the stereochemistry of the reaction only in a minor
合成了 6,7-Dihydro-1,6,11-trimethyl-5-oxo-5H-benzo[c]pyrido[2,3-e]azepin-1-ium iodide (11-Me-MMPA+I-) ,并证实盐中的轴向手性在室温下是稳定的。在用一对非对映二氢吡啶衍生物还原 11-Me-MMPA+ 时,反应面始终是其中包含阳离子羰基偶极子的面(即顺式选择性),而与还原剂的构型无关。经典意义上的空间位阻和其他因素仅在很小的部分对反应的立体化学有贡献。讨论了反应过渡态的合理分子间排列,以了解这种非空间立体化学的机制。