Synthesis of cyclohexadienylstannanes – Novel example of vinylic SRN1 mechanism: A theoretical and experimental study

The reaction of trimethyltinsodium (1) with 1-(diethoxyphosphoryl)oxy-1,3-cyclohexadienes in liquid ammonia under irradiation affords the corresponding 1-trimethylstannylcyclohexadienes. We suggest that these reactions occur by an SRN1 mechanism. On the other hand, 2-(diethoxyphosphoryl)oxy-1,3-cyclohexadiene reacts very slowly towards 1 and the substitution product decomposes under the reaction conditions employed. Thus, structurally similar compounds do not behave in the same way under ET conditions. We suggest that this behavior is mainly due to differences in spin density of their radical anions, which affect their fragmentation rates. Our results are supported by computational calculations.

Structurally similar (diethoxyphosphoryl)oxy-1,3-cyclohexadienes do not behave in the same way towards trimethyltinsodium in liquid ammonia, under ET conditions. We suggest a SRN1 mechanism for the substitution process. The dissimilar behavior is due to differences in spin density of their radical anions. Our experimental results are supported by computational calculations.Figure optionsDownload as PowerPoint slide