Microwave-promoted Alkane Inert Sp~3 C-H Functionalization

As transition metal-catalyzed inert sp~3 C-H activation has obtained a lot of achievements for the past few years,more and more organic chemist began to focus on it.However,metal-free catalysis inert sp~3 C-H activation was relatively small,this project mainly focused on this field,we studied the following two parts content by using microwave irradiation in inert sp~3 C-H functionalization,and got satisfactory results.An efficient procedure for the microwave irradiation direct to synthesis of ketone of unactivated sp~3 C-H bonds with TBP as an oxidant has been developed,this is a novel method for construction of C-C bonds via cross-dehydrogenative coupling(CDC)reaction with metal-free.Furthermore,this reaction provides a useful strategy for synthesis of aromatic ketone,various substrates could be well tolerated in this system with moderate chemical yields,alkanes include cyclopentane,cyclohexane,cycloheptane,cyclooctane and even aliphatic hydrocarbon,aromatic aldehydes include electron-donating groups and electron-withdrawing groups are able to get target products,so we managed to find a better tolerance and simple path for synthesis of aromatic ketone.By using this novel method,an alternative synthetic approach toward the key intermediates for the preparation of the pharmaceutically valuable oxaspiroketone derivatives was successfully established.We also study the mechanism via kinetic isotope effect and radical capture experiment.In the same way,a concise alkylation of ?-carbonyl compounds with alkane inert sp~3 C-H bonds has been developed on the condition that TBP as an oxidant and microwave irradiation.This is also a new way for alkylation of ?-carbonyl through cross-dehydrogenative coupling(CDC)reaction.This reaction without using any of metal catalyst could be smoothly occured whether mono-carbonyl or 1,3-dicarbonyl ketone,this is an efficient and convenient strategy for alkylation of carbonyl.In this paper,alkane inert sp~3 C-H activation for direct construction of C-C bonds via microwave irradiation promoted and TBP as an oxidant have been established,these reactions were accomplished under metal-free and without prefunctionalization,it also has another advantages such as easily obtained starting materials,easy operation,short reaction time and highly atom economy.