Hydrazone Radical Promoted Vicinal Difunctionalization of Alkenes and Trifunctionalization of Allyls: Synthesis of Pyrazolines and Tetrahydropyridazines
作者:Xiao-Yong Duan、Xiu-Long Yang、Ran Fang、Xie-Xue Peng、Wei Yu、Bing Han
DOI:10.1021/jo4016908
日期:2013.11.1
achieved by using TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) or DIAD (diisopropyl azodicarboxylate) as the hydrazone radical initiator as well as the carbon radical scavenger. Consequently, alkenes were difunctionalized to afford pyrazolines and tetrahydropyridazines via C–N forming 5-exo-trig and 6-exo-trig cyclizations, respectively, and allyls were trifunctionalized to afford pyrazolines via C–N forming
通过使用TEMPO(2,2,6,6-四甲基-1-哌啶基氧基)或DIAD(偶氮二异丙基二异丙酯)作为自由基引发剂和碳自由基清除剂,将自由基分子内加成至碳-碳双键。因此,烯烃经CN分别双官能化以形成吡唑啉和四氢哒嗪,分别形成5- exo - trig和6 exo - trig环化,烯丙基被三官能化通过CN形成吡唑啉并串联1,5-H-移位/ 5-外型- trig的不含金属的中性条件下的环化反应。