Synthesis of Bis(pyridodipyrimidines) as Autorecycling Redox Catalysts and Their Remarkable Turnover in the Oxidation of Alcohols

Article abstract of DOI:10.1021/ja00208a011

Bis(pyridodipyrimidines) (bis-PP's) as redox catalysts, in which two pyridodipyrimidine moieties are linked with polymethylene chains, have been synthesised by the condensation of bis(6-chloro-5-formyluracil-3-yl)alkanes with 6-alkylaminouracils.These bis-PP's oxidized alcohols more efficiently than monomeric pyridodipyrimidines to give the corresponding carbonyl compounds.Particularly, bis(7-methyl-10-(n-octyl)pyridodipyrimidin-3-yl)decane (5j) exhibitet remarkable oxidizing ability toward cyclopentanol as a turnover catalyst, and its maximum effective concentration(MEC) was determined.The MEC of 5j was 6.7E-5 mmol (59 μg)/3 ml of cyclopentanol at 115 deg C, and the MEC under introduction of oxygen (5 ml of oxygen/min) was 2E-4 mmol (177 μg)/3 ml of cyclopentanol at 100 deg C.Apart from the chemical yield of cyclopentanone, even an amount of only 2E-11 mmol (17.7 pg) of catalyst 5j oxidized cyclopentanol to give cyclopentanone in 13300000000000 percent yield based on the catalyst.This implies that the turnover number of catalyst 5j is 8.9E7 mol min^-1 (mol of catalyst)^-1, which would surpass that of bovine liver catalase, although the condition is quite different.