Insight into the Regioselectivity of Nucleophilic Ring-Opening of Azetidinium Ions Containing Quaternary Carbon Atoms
作者:Bruno Drouillat、Karen Wright、Olivier David、François Couty
DOI:10.1002/ejoc.201200890
日期:2012.10
A set of azetidinium ions each bearing a quaternary carbon atom α to the nitrogen atom were synthesized. These compounds were treated with three different nuclophiles: azide, cyanide and acetate anions. Examination of the regioselectivity in the ring-opening reactions demonstrated that attack at the quaternary position is intrinsically favored over that at the secondary position. However, these SN2
合成了一组氮杂环丁烷离子,每个离子在氮原子上带有一个季碳原子。这些化合物用三种不同的亲核试剂处理:叠氮化物、氰化物和乙酸根阴离子。对开环反应中的区域选择性的检查表明,四元位置的攻击本质上比第二位置的攻击更有利。然而,这些 SN2 反应对空间拥挤高度敏感,这可以抵消在季碳上反应的自然趋势。