15429-13-7Relevant academic research and scientific papers
Tf2O/TTBP (2,4,6-Tri-tert-butylpyrimidine): An Alternative Amide Activation System for the Direct Transformations of Both Tertiary and Secondary Amides
He, Qian,Ye, Jian-Liang,Xu, Fang-Fang,Geng, Hui,Chen, Ting-Ting,Chen, Hang,Huang, Pei-Qiang
, (2021/09/28)
Ten types of Tf2O/TTBP-mediated amide transformation reactions were investigated. The results showed that compared with pyridine derivatives 2,6-di-tert-butyl-4-methylpyridine (DTBMP) and 2-fluoropyridine (2-F-Pyr.), TTBP can serve as an alternative amide activation system for the direct transformation of both secondary and tertiary amides. For most surveyed examples, higher or comparable yields were generally obtained. In addition, Tf2O/TTBP combination was used to promote the condensation reactions of 2-(tert-butyldimethylsilyloxy)furan (TBSOF) with both tertiary and secondary amides, the one-pot reductive Bischler-Napieralski-type reaction of tertiary lactams, and Movassaghi and Hill's modern version of the Bischler-Napieralski reaction. The value of the Tf2O/TTBP-based methodology was further demonstrated by the concise and high-yielding syntheses of several natural products.
A direct and general method for the reductive alkylation of tertiary lactams/amides: Application to the step economical synthesis of alkaloid (-)-morusimic acid D
Xiao, Kai-Jiong,Wang, Yu,Huang, Ying-Hong,Wang, Xiao-Gang,Huang, Pei-Qiang
, p. 8305 - 8311 (2013/09/24)
Full details of the direct and general method for the reductive alkylation of tertiary lactams and amides to give tertiary sec-alkylamines are presented. This one-pot method consists of in situ activation of a lactam or an amide with Tf2O/DTBMP, addition of a Grignard reagent, and reduction of the resulting iminium intermediates. Alkyl, benzyl, and aryl Grignard reagents and several reductants or reducing conditions (LiAlH4, NaBH4, Hantzsch ester, Bu3SnH, Pd(OH)2/C, H2) could be used effectively. Reductive alkylations of substituted lactams demonstrated good to excellent 1,3-asymmetric induction to provide the corresponding di- or trisubstituted pyrrolidine/piperidine in 6:1 (LiAlH4), 11:1 (Et 3SiH), and 20:1 (catalytic hydrogenation) cis/trans diastereoselectivity, respectively. The versatility of this methodology was demonstrated by its application in the concise stereoselective synthesis of piperidine alkaloid (-)-morusimic acid.
Versatile one-pot reductive alkylation of lactams/amides via amide activation: Application to the concise syntheses of bioactive alkaloids (±)-bgugaine, (±)-coniine, (+)-preussin, and (-)-cassine
Xiao, Kai-Jiong,Wang, Yu,Ye, Ke-Yin,Huang, Pei-Qiang
supporting information; experimental part, p. 12792 - 12796 (2011/02/22)
Direct entry: One-pot reductive alkylation of lactams/amides with Grignard reagents has been realized via lactam/amide activation with Tf2O. This method opens a direct entry to α-alkylated amines. The versatility of the method is illustrated by the concise syntheses of bioactive alkaloids (±)-bgugaine, (±)-coniine, (+)-preussin, and (?)-cassine.
