N-Acyl-N-tosylhydrazine as a Synthon To Construct Tetrasubstituted Carbon Centers Possessing a Nitrogen Group
N-Acyl-N-tosylhydrazine as a Synthon To Construct Tetrasubstituted Carbon Centers Possessing a Nitrogen Group
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DOI：
10.1002/ejoc.201402650
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发表时间：
2014-08
影响因子：
2.8
通讯作者：
K. Namba;Yoshihiro Shobo;K. Fujimoto;Isamu Shoji;Masahiro Yoshida;K. Tanino
中科院分区：
文献类型：
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作者：
K. Namba;Yoshihiro Shobo;K. Fujimoto;Isamu Shoji;Masahiro Yoshida;K. Tanino
开发了使用合成子N-酰基-N-甲苯磺酰肼的新的卤代酰肼化和酰肼基钯化反应。β，γ-不饱和N-酰基-N-对甲苯磺酰肼的分子内溴酰肼化反应容易得到含有四取代碳中心的吡唑烷酮环体系，N-酰基-N-对甲苯磺酰肼的伯胺是一种软亲核试剂。γ，δ-不饱和N-酰基-N-对甲苯磺酰肼的溴酰肼化反应也是O-环化生成内酯环，而不是N-环化生成氢化哒嗪环体系;然而，分子内酰肼钯化反应主要生成氢化哒嗪环。所建立的催化肼基钯化反应适用于几种多取代烯烃，以构建具有氮基团的四取代碳中心。
New halohydrazidation and hydrazidopalladation reactions were developed that use the synthon N-acyl-N-tosylhydrazine. The intramolecular bromohydrazidation reactions of β,γ-unsaturated N-acyl-N-tosylhydrazines readily afforded pyrazolidinone ring systems that contained a tetrasubstituted carbon center, and the primary amine of the N-acyl-N-tosylhydrazine was shown to be a soft nucleophile. The similar bromohydrazidation reaction of γ,δ-unsaturated N-acyl-N-tosylhydrazine resulted in O-cyclization to give a lactone ring instead of N-cyclization to give a hydropyridazine ring system; however, the intramolecular hydrazidopalladation reaction predominantly afforded a hydropyridazine ring. The established catalytic hydrazidopalladation reaction was applicable to several multisubstituted alkenes to construct a tetrasubstituted carbon center possessing a nitrogen group.