诺加霉素(NOG)是蒽环类苷类天然产物的一员;尚未有全合成的报道,并且对 A 环糖和 D 环糖的苷元取代模式和特性如何影响抗癌活性和毒性的了解也很少。本文报告了 NOG 模块化方法的进展,该方法可以实现系统的结构-活性关系研究。关键步骤包括区域选择性苯炔环加成和还原开环,以组装用于类似物合成的多功能 AB 核。
诺加霉素(NOG)是蒽环类苷类天然产物的一员;尚未有全合成的报道,并且对 A 环糖和 D 环糖的苷元取代模式和特性如何影响抗癌活性和毒性的了解也很少。本文报告了 NOG 模块化方法的进展,该方法可以实现系统的结构-活性关系研究。关键步骤包括区域选择性苯炔环加成和还原开环,以组装用于类似物合成的多功能 AB 核。
such heterocycles is the (3 + 2) cycloaddition reaction of benzynes with 1,3-dipolar compounds. However, the reactions of unsymmetrically substituted benzynes generally show low selectivity and hence yield mixtures of two regioisomers. In this paper, we describe the synthesis of both regioisomers of multisubstituted benzo-fused azole derivatives such as benzotriazoles, 1H-indazoles, and benzo[d]isoxazoles
3-Borylbenzynes were generated in situ from 6-boryl-2-iodophenyl trifluoromethanesulfonates using i-PrMgCl·LiCl and applied to Diels–Alder reactions with substituted furans and pyrroles. The reactions allowed good functional group compatibility and produced the cycloadducts in high yields with high distal selectivities. Effective conversion of the boryl group of the products was achieved. A series
B+[4+2]: 3‐Borylbenzynes undergo Diels–Alder reactions with substituted furans and pyrroles to give highly functionalized arylboronic acid derivatives with either good or exclusive regioselectivities (see picture). The effect of the boryl group on the regioselectivity arises from electronic rather than steric effects.
B + [4 + 2]:3-甲硼烷基苯甲醛与取代的呋喃和吡咯进行Diels-Alder反应,得到具有良好或排他性区域选择性的高度官能化的芳基硼酸衍生物(参见图片)。硼烷基对区域选择性的影响来自电子效应而不是空间效应。