Caudill Laboratories, Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States.
U.S. Army Research Office, P.O. Box 12211, Research Triangle Park, North Carolina 27709, United States.
Org Lett. 2022 Jun 17;24(23):4135-4139. doi: 10.1021/acs.orglett.2c01243. Epub 2022 Jun 2.
A novel diastereoselective, Lewis acid catalyzed 1,6-difunctionalization of galactose and mannose derivatives has been developed in one pot, via sequential nucleophile additions. Our studies point to the formation of a 3,6-anhydrosugar intermediate as key to the 1,6-site-selectivity. Starting material-specific reactivity occurs when competitive ring-opening C-O cleavage is possible, owed to basicity and stereoelectronic stabilization differences. Lastly, Mayr nucleophilicity parameter values helped predict which reaction conditions would be most suitable for specific nucleophiles.
已开发出一种新型非对映选择性路易斯酸催化的半乳糖和甘露糖衍生物一锅法 1,6-双官能化反应，通过顺序亲核加成实现。我们的研究表明，形成 3,6-脱水糖中间体是 1,6-位点选择性的关键。当可能发生竞争性开环 C-O 裂解时，由于碱性和立体电子稳定化差异，会出现基于起始原料的反应性。最后，Mayr 亲核性参数值有助于预测哪些反应条件最适合特定亲核试剂。
