Selective Transfer Hydrogenation of Polyenes to Monoenes Catalysed by Shvo's Catalyst

This paper reports the highly selective transfer hydrogenation (TH) of polyunsaturated hydrocarbons to monoolefins with isopropanol as hydrogen source, catalysed by Shvo's catalyst with selectivities of up to 98% at full conversion. Although being a well‐established catalyst, this reaction is unprecedented in the case of Shvo's complex. A fast isomerisation of the CC double bonds to conjugated dienes is followed by the selective reduction to monoenes at elevated temperatures up to 150°C in a pressure‐stable microwave synthesiser, reaching a maximum turnover frequency (TOF) of 274 h −1 . Optimisation of the reaction conditions has demonstrated that controlling the reaction temperature and time enables the catalyst system to switch between isomerisation, semihydrogenation and full hydrogenation. Amongst others, 1,5‐cyclooctadiene and 1,5,9‐cyclododecatriene yielded 97% and 92% of the respective monoenes at full conversion. Furthermore, the possibility of catalyst separation and recycling via recrystallisation of the employed catalyst complex is demonstrated.