Transition Metal Catalyzed Ortho C-H Functionalization Of 2-Arylquinazoline Derivatives

Quinazoline skeleton compounds are an important class of nitrogen-containing heterocyclic compounds which are widely present in natural products.In recent decades Studies have shown that quinazoline compounds are of great biological activity and excellent performance,that are being paid more and more attention by researchers.Therefore,it is important to develop and study quinazoline compounds.The transition metal C-H functionalization reaction is an important hot-topic recently.Compared with the previous functionalization reaction,the C-H functionalization reaction does not need to first functionalize the compound to form a halogen compound,and further convert the halogen into other groups,but Direct activation of the C-H bond directly through the transition metal provides the desired functionalization in one step.Not only saves time,but also saves costs.Therefore,the transition metal C-H functionalization reaction is widely favored by organic chemists.The quinazoline compounds are a kind of nitrogen-containing direct group,which can directly realize the sp~2 C-H functionalization reaction of 2-aryl group.Our group is committed to developing a synthesis method of quinazoline compounds to establish a quinazoline molecular library;Based on previous experience,we have further studied the functionalization of the quinazoline 2 aryl group.This paper mainly studies three aspects.(1)Using 2,4-diarylquinazoline as raw material and malononitrile as cyanogen source,we have developed Rh/Cu catalyzed one-pot efficiently synthesis of2-(o-cyanoaryl)-4-aryl A method of quinazoline.(2)Using 2,4-diarylquinazoline as raw material and paraformaldehyde as a methyloxlation reagent,Ru-catalyzed ortho C-H methyloxlation reaction was developed.The reaction conditions were mild and different conditions were going,achieve selective single and double substitution.(3)Using 2-aryl quinazolinone and 2-alkynyl acetate as raw materials,the ruthenium-catalyzed quinazolinone ortho C-H selective allenylation and Aza-Michael addition reaction were developed.The reaction contains mild condition,highly efficient,selective which synthesis of single,double substituted and Aza-Michael addition products advantages.