Mononuclear Pseudostannatranes Possessing Unsymmetrical [4.4.3.0]Tridecane Cage: Experimental and Theoretical Aspects of Reverse Kocheshkov Reaction in Phenyl Pseudostannatrane.

The synthetic protocols, structural aspects, and spectroscopic aspects of mononuclear pseudostannatranes possessing a [4.4.3.0]tridecane cage have been reported. A tripodal ligand N(CHCHOH){CH(2--Bu-4-Me-CHOH)} (HL) having unsymmetrical arms was reacted with -butyltrichlorostannane, phenyltrichlorostannane, and tin tetrachloride under different solvent systems to obtain pseudostannatranes (-). The reaction of -butyltrichlorostannane and the ligand in CHOH/Na/THF yielded an aqua complex of pseudostannatrane [LSnBu(HO)] (), which was crystallized as its acetone solvate (i.e ·MeCO). However, the same reactants yielded methanol complex [LSnBu(CHOH)] () when the reaction was carried out in the NaOCH/CHOH system. Similarly, the reaction of phenyltrichlorostannane and the ligand under these solvent systems yielded pseudostannatranes, i.e., an aqua complex [LSnPh(HO)] () and a methanol complex [LSnPh(CHOH)] () (where was crystallized as ·MeCO). The reaction of tin tetrachloride and the ligand in the EtN/THF system resulted in the formation of pseudostannatrane [LHSnCl] (). A similar product was isolated as its triethylamine solvate (·) due to the disproportion reaction when PhSnCl was reacted with the ligand in the EtN/CHCH system, which demonstrates the first report on the reverse Kocheshkov reaction in pseudostannatranes. The experimental findings on the formation of · due to the reverse Kocheshkov reaction have been corroborated with Sn NMR spectroscopy and density functional calculations that provide insightful information about the underlying details of the reaction route.