醋酸酐做促进剂，三价铟催化的醛和活性亚甲基的Knoevenagel Condensation反应
醋酸酐和催化量的三氯化铟可以显著地促进多种醛和活性亚甲基的Knoevenagel condensation反应，这个催化体系适合各种给电子基团和吸电子基团，
芳香杂环的醛和共轭的醛，脂肪醛；反应的核心是在铟催化下酸酐和醛形成的偕二乙酸酯中间体的形成。
Indium(III)-Catalyzed Knoevenagel Condensation of Aldehydes and Activated Methylenes
Using Acetic Anhydride as a Promoter
The combination of a catalytic amount of InCl3 and acetic anhydride remarkably promotes the Knoevenagel condensation of a variety of aldehydes and activated methylene compounds. This catalytic system accommodates aromatic aldehydes containing a variety of electron-donating and -withdrawing groups, heteroaromatic aldehydes, conjugate aldehydes, and aliphatic aldehydes. Central to successfully driving the condensation series is the formation of a geminal diacetate intermediate, which was generated in situ from
an aldehyde and an acid anhydride with the assistance of an indium catalyst.
Yohei Ogiwara , Keita Takahashi , Takefumi Kitazawa , and Norio Sakai *
Department of Pure and Applied Chemistry, Faculty of Science and Technology, Tokyo University of Science (RIKADAI), Noda, Chiba 278-8510, Japan
J. Org. Chem
