Fast and reversible migrations of N,S-centered groups around the perimeter of cyclopropene and cycloheptatriene rings
作者:V. I. Minkin、I. E. Mikhailov、G. A. Dushenko、O. E. Kompan、A. Zschunke
DOI:10.1007/bf02498157
日期:1998.5
and mechanism of circumambulatory rearrangements of N-centered (NCS) and S-centered (SPh, SC3Ph3, SC(OEt)=S) groups in corresponding derivatives of 1,2,3-triphenylcyclopropene and cycloheptatriene were studied by dynamic1H and13C NMR spectroscopy. Migrations of the isothiocyanate group occur by the dissociation-recombination mechanism with intermediate formation of a tight ionic pair. Migrations of
1,2,3-三苯基环丙烯和环庚三烯的相应衍生物中N-中心(NCS)和S-中心(SPh, SC3Ph3, SC(OEt)=S)基团环行重排的动力学和机制研究了动态1H和13C核磁共振光谱学。异硫氰酸酯基团的迁移通过离解-重组机制发生,中间形成紧密的离子对。环丙烯和环庚三烯环周边的苯硫基迁移是通过 1,2-移位机制发生的。发现O-乙基二硫代碳酸酯基团在S-(1,2,3-三苯基环丙烯-3-基)-O-乙基二硫代碳酸酯中的重排通过3,3-σ迁移机制发生。通过X射线分析研究了O-乙基S-(1,2,3-三苯基环丙烯-3-基)二硫代碳酸酯的分子和晶体结构。