Base-induced reversible H(2) addition to a single Sn(ii) centre

A range of amines catalyse the oxidative addition (OA) of H(2) to [(Me(3)Si)(2)CH](2)Sn (1), forming [(Me(3)Si)(2)CH](2)SnH(2) (2). Experimental and computational studies point to ‘frustrated Lewis pair’ mechanisms in which 1 acts as a Lewis acid and involve unusual late transition states; this is supported by the observation of a kinetic isotope effect [Image: see text] for Et(3)N. When DBU is used the energetics of H(2) activation are altered, allowing an equilibrium between 1, 2 and adduct [1·DBU] to be established, thus demonstrating reversible oxidative addition/reductive elimination (RE) of H(2) at a single main group centre.