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-C 6 H 4 Bu t ) with a series of inert, unsaturated small molecule substrates have been carried out. Compound 1 reduces Bu t NC: to give the singlet biradicaloid 1,3-disilacyclobutanediyl [{ArC(NDip) 2 }Si(μ-CNBu t )] 2 3, which can be oxidised by 1,2-dibromoethane to give [{ArC(NDip) 2 }(Br)Si(μ-CNBu t )] 2 4. Disilylene 1 reduces two molecules of ethylene to give an unprecedented disilabicyclo[2.2.0]hexane, [{ArC(NDip) 2 }Si(μ-C 2 H 4 )] 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 (μ-C 2 H 4 ) 7. Compound 1 reduces CO 2 , generating CO, and the oxo/carbonate-bridged disilicon(IV) system, {ArC(NDip) 2 }Si(μ-CO 3 ) 2 (μ-O)Si{(NDip) 2 CAr} 10, while its reaction with N 2 O proceeds via generation of N 2 , and a hydrogen abstraction process, to give the oxo/hydroxy disilicon(IV) species, [{ArC(NDip) 2 }(HO)Si(μ-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.