Research On Aerobic Alkene Oxidations Based On Organic Nitrite Cocatalyst

Alkenenes are widely isolated from oil and coal,and the corresponding bifunctional products,aldehydes and ketones via olefins conversion have important applications in both industry and medicine,and therefore the oxidation reaction of olefins has always been an important research works.Among of them,the selective oxidation of olefins has a more extensive application in industry and is also a challenging works.Since Wacker company developed the PdCl2/CUCl2/O2/DMF/H2O catalytic system in 1959,a serious of catalytic systems have been developed to switchable the selectivity of olefin oxidation.However,the systems often need to be added to the environmental hazards and expensive copper/silver/BQ/PhI(OAc)2 and other co-oxidants as intermediary system.Therefore,it was particulary important to develop a more environmentally,friendly,inexpensive,readily available and green cocatalyst system.The following four parts research focused on the selective oxidation of olefins and the development of a greener cocayalyst intermediary system:1.This part studied on the two issues of how to control the anti-Markovnikov Wacker oxidation selectivity of the olefins and how to achieve catalyst recycling without adding copper cocatalyst.The mechanism was re-explored through kinetic study experiments and controlled experiments,and then this method was developed into a practical synthesis methodology,achieving anti-Markovnikov selective Wacker oxidation without copper/silver.2.Through the slight change of reaction conditions,we can also switchable the Wacker oxidation reaction to get ketones as the major product.This method has better selectivity and yield.On this basis,regioselectivity controlled Wacker oxidation reaction under the same catalytic system was achieved.3.The palladium catalyzed dihydroxylation of olefins with air or oxygen as oxidant is achieved.As a powerful supplement of dihydroxulation of Upjohn with OsO4 as a catalyst and Prevost-Woodward dihydroxylation with I2 and silver carboxylate as reagents,the dihydroxylation of olefins under air oxidation without copper,silver and other transition metal reagents was realized for the first time.This method can be used to prepare large amount of vicinal diol,and is practical.4.On the basis of anti-Markovnikov Wacker oxidation,various substituted indoles were prepared by Pd-tBuONO co-catalysted.Starting from 2-vinylaniline,C4-C7 substituted and C2 substituted indole can be effectively prepared,and which was the most widely used synthetic method to substituted indole currently.This method is applied to drug synthesis at more than ten grame-scales.5.Aldehydes or ketones prepared by Wacker oxidation are important chemical products,one of which is used to synthesis of terminal or secondary alcohols.In one-pot reaction,it was found that NaBH4 can't reductive aldehydes and ketones in tBuOH and other solvents.Therefore,a cheap and practical catalytic synthesis method of ion pair for promoting the reduction of aldehydes and ketones by NaBH4 has been developed,which can be highly efficiently performed in both weak polar and nonpolar solvents.