Evidence of Transannular Bonding Interaction between Two Sulfur Atoms on Photolysis of Naphtho[1,8-<i>ef</i>][1,4]dithiepins
作者:Takayoshi Fujii、Ohgi Takahashi、Naomichi Furukawa
DOI:10.1021/jo960517m
日期:1996.1.1
of this reaction was investigated by examining the effect of sensitization and light intensity. The results indicate that the reaction may proceed by a one-photon process from an excited singlet state. Ab initio calculations were carried out on model compound 7, and it was shown that the excitation to the S(1) state causes a bonding interaction between the two sulfur atoms, making the reaction possible
萘并[1,8-ef] [1,4]二巯基吡啶5是在乙酰丙酮铜存在下,萘并[1,8-de] -1,3-二硫辛3与重氮丙二酸二乙酯反应制得的。2,3-二氢-2,2-双(乙氧基羰基)-3-苯基萘并[1,8-ef] [1,4]二噻吩(5a)的X射线晶体分析表明,SS距离短于它们的范德华半径之和,表明化合物5在两个硫原子之间具有很强的贯穿空间相互作用。在室温下用500 W高压汞灯(313 nm)直接照射5,定量得到相应的烯烃6和萘[1,8-cd] -1,2-二硫醇(1)。消耗5a和形成6a和1的量子产率为0.34。通过检查敏化和光强度的影响,研究了该反应的机理。结果表明,反应可以从激发的单重态通过单光子过程进行。对模型化合物7进行了从头算的计算,结果表明,激发到S(1)状态会引起两个硫原子之间的键相互作用,从而使反应成为可能。