Azophilic addition of alkyllithium reagents to fluorenimines. The synthesis of secondary amines

…, R Srinivasan, JA Katzenellenbogen

Index: Dai, Wei; Srinivasan, Rajgopal; Katzenellenbogen, John A. Journal of Organic Chemistry, 1989 , vol. 54, # 9 p. 2204 - 2208

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Citation Number: 23

Abstract

N-Alkyl-and N-arylfluorenimines undergo azophilic addition with n-BuLi to give N-butyl-N- alkyl-or N-butyl-N-aryl-9-aminofluorene systems. The fluorenyl group can then be hydrogenolyzed, furnishing the secondary amine. The selectivity for azophilic (vs carbophilic) addition ranges from 80 to 100% for the N-alkylfluorenimines to 24-29% for the N-arylfluorenimines. The decreased azophilic selectivity of the N-arylfluorenimines can be ...