The oxidations of the title perchlorates, bearing the sterically diverse 6'-substituents (H, Me, Et, i-Pr, n-Bu, t-Bu and Ph) in two series with the same 4-substituents (Ph and t-Bu) lead to pairs of isomeric 3',5-disubstituted (Z)-1'-phenyl-3'-(2-phenylimidazo[1,2-a]pyridin-3-yl)prop-2'- en-1'-ones and 3,6'-disubstituted [5-phenyl-1-(6'-pyridin-2'-yl)-1H-pyrrol-2-yl](phenyl)methanones except where the both variable substituents are t-Bu and then only pyrrolic product is formed. Considering steric interactions of the substituents in some intermediate and/or transition states a multistep mechanism for the oxidative transformation is proposed and supported by model PM3-PECI calculations of some radical intermediates.
标题中的高氯酸盐氧化反应,带有空间异构的6'-取代基(H、Me、Et、i-Pr、n-Bu、t-Bu和Ph)分为两个系列,其4-取代基(Ph和t-Bu)相同,导致成对的同分异构体3',5-二取代(Z)-1'-苯基-3' -(2-苯基咪唑[1,2-a]吡啶-3-基)丙-2'-烯-1'-酮和3,6'-二取代[5-苯基-1-(6'-吡啶-2'-基)-1H-吡咯-2-基](苯基)甲酮,除非两个可变取代基都是t-Bu,然后只形成吡咯产物。考虑到一些中间体和/或过渡态中取代基的空间相互作用,提出了一种多步骤机制的氧化转化,并通过一些自由基中间体的模型PM3-PECI计算来支持。