Facile activation of inert small molecules using a 1,2-disilylene

Reactions of the known amidinate stabilised 1,2-disilylene, ({ArC(NDip)(2)}Si](2) 1 (Dip = 2,6-diisopropylphenyl, Ar = 4-C6H4But) with a series of inert, unsaturated small molecule substrates have been carried out. Compound 1 reduces (BuNC)-N-t: to give the singlet biradicaloid 1,3-disilacyclobutanediyl [{(ArC(NDip)(2)}Si(mu-CNBut)](2) 3, which can be oxidised by 1,2-dibromoethane to give [{ArC(NDip)(2))(Br)Si(mu-CNBut)](2) 4. Disilylene 1 reduces two molecules of ethylene to give an unprecedented disilabicyclo[2.2.0]hexane, [{ArC(NDip)(2))Si(mu-C2H4)](2) 5. In contrast, only one molecule of ethylene inserts in the Ge-Ge bond of the digermylene analogue of 1, viz. [{ArC(NDip)(2)}Ge](2) 6, leading to the formation of the bis(germylene), [{ArC(NDip)(2))Ge](2)(mu-C2H4) 7. Compound 1 reduces CO2, generating CO, and the oxo/carbonate-bridged disilicon(IV) system, {ArC(NDip)(2)}Si(mu-CO3)(2) (mu-O)Si{(NDip)(2)CAr} 10, while its reaction with N2O proceeds via generation of N-2, and a hydrogen abstraction process, to give the oxo/hydroxy disilicon(IV) species, [{ArC(NDip)(2))(HO)Si(mu-O)](2) 11. This study highlights new small molecule activation chemistry for 1,2-disilylenes, which could lead to further adoption of compound 1 as a potent reducing reagent for the transformation of inert unsaturated molecules into value added products.