Highly Diastereoselective Synthesis of 1-Pyrrolines via SnCl4-Promoted [3 + 2] Cycloaddition between Activated Donor–Acceptor Cyclopropanes and Nitriles

Activated donor–acceptor cyclopropanes underwent formal [3 + 2] cycloaddition with nitriles in the presence of SnCl4. The product 1-pyrrolines were isolated as single cis-diastereomers in moderate to good yields.活化供体-受体环丙烷（activated donor–acceptor cyclopropanes）在四氯化锡（SnCl4）存在条件下，与腈类（nitriles）发生形式[3+2]环加成反应。产物1-吡咯啉（1-pyrrolines）以单一顺式非对映异构体形式被分离得到，收率为中等至良好。