Cy2NH·HX-Promoted Cyclizations of o-(Alk-1-ynyl)benzoates and (Z)-Alk-2-en-4-ynoate with Copper Halides to Synthesize Isocoumarins and α-Pyrone - Liang, Yun; Xie, Ye-Xiang; Li, Jin-Heng (Synthesis, 2007)