Graduate School of Science and Engineering, Saitama University, 255 Shimo-Ohkubo, Sakura Ward, Saitama City, Saitama 338-8570, Japan.
J Org Chem. 2011 Jul 1;76(13):5413-28. doi: 10.1021/jo200834n. Epub 2011 Jun 2.
Twenty chiral 1,3-amino sulfonamides of two classes (2a-i and 3a-k) have been prepared from (-)-cis-2-benzamidocyclohexanecarboxylic acid (1) and studied as ligands for catalytic enantioselective addition of Et(2)Zn to a variety of aromatic and aliphatic aldehydes. The ligands 2 and 3 are regioisomers in which the position of the amine and sulfonamide groups is exchanged. Each class of ligands with the same chirality was shown to afford sec-alcohols with the opposite stereochemistry. Structural surveys revealed that the combination of tertiary amino and p-toluenesufonylamido groups works most effectively for the reaction. Through optimization of the structural and reaction conditions, the best ligands quantitatively provided both enantiomeric secondary alcohols in good to excellent enantioselectivity of up to 94% and 98% ee for (S)- and (R)-enantiomers, respectively.
已经合成了两类（2a-i 和 3a-k）共 20 个手性 1,3-氨基磺酰胺，它们是从（-）-顺式-2-苯甲酰胺环己烷羧酸（1）衍生而来的，并被研究作为手性催化对映选择性加成 Et(2)Zn 到各种芳香族和脂肪族醛的配体。配体 2 和 3 是区域异构体，其中胺和磺酰胺基团的位置被交换。每类具有相同手性的配体都显示出相反的立体化学，提供了 sec-醇。结构调查表明，叔氨基和对甲苯磺酰氨基基团的组合对反应最有效。通过对结构和反应条件的优化，最佳配体定量地以高达 94%和 98%ee 的对映选择性，分别提供了两种对映体的手性仲醇。
