Highly selective hydroformylation of 3,3,3-trifluoropropene to 4,4,4-trifluorobutanal using Rh/Xantphos catalyst

Synthesis of 4,4,4-trifluorobutanal by Rh-catalyzed hydroformylation of 3,3,3-trifluoropropene with bis(4,5-diphenylphosphino)xanthene as a ligand was investigated. The uses of [Rh(OH)(cod)]2 (cod = 1,5-cyclooctadinene) and dimethylformamide in CO/H2 = 75/25 mixed gas under atmospheric pressure at 80 °C for 15 h provided the highest aldehyde yield 90%. The molar ratio of linear aldehyde (4,4,4-trifluorobutanal) to branched aldehyde (3,3,3-trifluoro-2-methylpropanal) was 99/1. The successive addition of dimethylformamide solution of 3,3,3-trifluoropropene under atmospheric pressure revealed that 4,4,4-trifluorobutanal formation increased linearly with the reaction time and the total turnover number reached 500 after 10 h retaining 99% selectivity of 4,4,4-trifluorobutanal at 80 °C.