Manganese 2-phosphinophosphinine precatalysts for methanol/ethanol upgrading to isobutanol.

Two Mn-phosphinophosphinine complexes were synthesised from reaction of the proligand with [MnBr(CO)] at 80 °C for 2 h; 2-diphenylphosphino-3-methyl-6-trimethylsilylphosphinine manganese tricarbonyl bromide (2TMS) and 2-diphenylphosphino-3-methyl-phosphinine manganese tricarbonyl bromide (2H). P{H} NMR spectroscopy revealed characteristic chemical shifts for the phosphinine and phosphine donors bound to Mn (255.4 and 23.