Novel sequence of two base-catalyzed 1,3 proton shifts and [1,2] Wittig rearrangement in the synthesis of 2,4-bis-(trifluoromethyl)-6-phenylpyridine
作者:Vadim A. Soloshonok、Hironari Ohkura、Manabu Yasumoto
DOI:10.1016/j.jfluchem.2006.01.010
日期:2006.6
was found to proceed via intermediate formation of (R, 4E, 6Z)-5,7-bis-(trifluoromethyl)-2,3-dihydro-3-phenyl-1,4-oxazepine which further underwent a base-catalyzed 1,3-proton shift reaction followed by [1,2] Wittig rearrangement giving rise to 2,4-bis-(trifluoromethyl)-6-phenylpyridine.
发现1,1,1,5,5,5-六氟-2,4-戊二酮与(R)-苯基甘氨醇的反应是通过(R,4 E,6 Z)-5,7-的中间形成进行的双-(三氟甲基)-2,3-二氢-3-苯基-1,4-氧杂氮平,进一步进行了碱催化的1,3-质子转移反应,然后进行[1,2] Wittig重排,得到2,4 -双-(三氟甲基)-6-苯基吡啶。