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。
Generation of 3-borylbenzynes, their regioselective Diels–Alder reactions, and theoretical analysis
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