[3 + 2] Cycloaddition of nitrile oxides to dichloropropenes and 1,3‐dichlorobut‐2‐ene: A regioselectivity issue
作者:Alexandra N. Shilova、Nina S. Shatokhina、Evgeniy V. Kondrashov
DOI:10.1002/jhet.4787
日期:2024.4
The reaction of nitrile oxides with 2,3-dichloroprop-1-ene, 1,3-dichloroprop-1-ene, and 1,3-dichlorobut-2-ene leads to 5-(chloromethyl)isoxazoles, 4-(chloromethyl)isoxazoles, or to mixtures of both regioisomers. The direction of cycloaddition and reactivity of substrate is determined by the steric hindrance at the terminal carbon atom of the alkene double bond. It has been found that the isomeric products
氧化腈与 2,3-二氯丙-1-烯、1,3-二氯丙-1-烯和 1,3-二氯丁-2-烯反应生成 5-(氯甲基)异恶唑、4-(氯甲基)异恶唑,或两种区域异构体的混合物。环加成的方向和底物的反应性由烯烃双键末端碳原子的空间位阻决定。研究发现,氧化腈与1,3-二氯丙烯环加成的异构产物具有显着不同的脱氯化氢能力。环加成的区域选择性和底物相对反应性的实验数据与量子化学计算的结果一致。