Sequential Reactions of Trimethylsilyldiazomethane with 4‑Alkenyl Ketones and Aldehydes Catalyzed by Lewis Bases

A sequence of a carbonyl addition between 4-alkenyl ketones and aldehydes with trimethylsilyldiazomethane followed by a 1,3-Brook rearrangement and an intramolecular 1,3-dipolar cycloaddition was promoted by Lewis bases tetrabutylammonium triphenyldifluorosilicate (TBAT) or potassium tert-butoxide (KO-t-Bu). Through these concatenated bond-forming processes, a variety of novel bi- and tricyclic Δ1-pyrazolines were synthesized.以路易斯碱四丁基三苯基二氟硅酸钾（TBAT）或叔丁醇钾（KO-t-Bu）为促进剂，可介导4-烯基酮、醛与三甲基硅基重氮甲烷的羰基加成串联反应，该反应序列依次经历1,3-布鲁克重排与分子内1,3-偶极环加成过程。通过上述串联成键过程，成功合成了多种新型双环及三环Δ¹-吡唑啉类化合物。