Efficient Preparation of Optically Active Highly Strained Azirines and Synthesis of Natural and Unnatural Amines and Amino Acids

已经开发了从吖丙啶开始的立体选择性反应。在氮丙啶与AlMe_3反应合成氮丙啶的加氢反应中，开环反应只发生在3位，生成β-氨基醇。3-位的立体化学是保留还是反转取决于所用的溶剂。一个有趣的相关性被发现之间的介电常数的溶剂和非对映体过量值（% de）。我们还成功地合成了新的氮杂环丙烷羧酸酯。Β-酮酸酯与羟胺反应得到相应的肟。用对甲苯磺酰氯和三乙胺处理后得到新的氮丙啶羧酸酯，在-40 ℃下，固定化脂肪酶催化氮丙啶的动力学拆分反应速率虽有所提高，但对映体选择性较硅藻土载体有所降低。Vario 关于我们 考察了US酰化剂以提高对映选择性。使用丁酸乙烯酯，E值提高到96，催化周转数提高了10倍以上。我们以前发现，在脂肪酶催化的动力学拆分，降低反应温度的结果增加对映体选择性。在本研究中，我们发现，对映选择性增加根据热力学方程，但低于临界温度，对映选择性根据另一个方程下降。我们称这个温度为“逆温”。在吖丙啶的动力学拆分中，溶剂的改变会导致转化温度的改变。此外，脂肪酶的变化也导致了转化温度的移动。研究了转化温度与溶剂各参数之间的关系。为了研究氮杂环丙烷的溶剂化模式，测量了低温NMR谱。结果表明，影响转化温度的因素是复杂的，受脂肪酶种类和底物种类的影响。少

Stereoselective reactions starting from azirines have been developed. In the hydrogenation of aziridine, which was synthesized by the reaction of azirine with AlMe_3, the ring-opening reaction took place at the 3-position specifically to give only β-amino alcohol. Whether the stereochemistry at the 3-position was retained or inverted depended on the solvent used. An interesting correlation was found between the dielectric constants of the solvents and the diastereomeric excess values (% de). We also succeeded in the synthesis of new azirine carboxylic acid ester. Β-Keto ester was reacted with hydroxyl amine to give the corresponding oxime. Treatment with tosyl chloride and triethylamine afforded the new azirine carboxylic acid ester.Although the reaction rate of the lipase-catalyzed kinetic resolution of azirine at -40 ℃ was improved by using lipase immobilized to porous ceramics support, the enantioselectivily was decreased as compared to that obtained with the lipase on Celite. Vario … More us acylating agents were examined to improve the enantioselectivity. Using vinyl butyrate, the E value was increased up to 96, and the catalytic turnover number was improved by more than 10-fold.We have previously found in the lipase-catalyzed kinetic resolution that lowering the reaction temperature results in an increase in enantioselectiviry. In this study, we found that the enantioselectivity is increased according to a thermodynamic equation, but below a critical temperature, the enantioselectivity is decreased according to another equation. We call this temperature "the inversion temperature". In the kinetic resolution of azirine, the change of solvent resulted in the change of the inversion temperature. Furthermore, the change of lipase also resulted in the shift of the inversion temperature. The correlation between the inversion temperatures and various parameters of the solvents was investigated. To investigate the salvation mode for azirine, low-temperature NMR spectra were measured. As a result, complicated factors that are affected by the kinds of lipase and substrate seemed to be responsible for the inversion temperature. Less