Construction Of Furan/Pyran Heterocyclic Compounds Based On Aldol Domino Cyclization Reactions

Compounds with heterocyclic structures such as furan,thiophene and quinoline are present in many natural products and constitute their key frameworks.Among them,optically active multifunctional heterocyclic compounds have good biological activity,which attracted a large number of chemical and pharmaceutical researchers concerns.The subject consists of the following two parts:(1)Highly selective synthesis of optically active indole spirofuran ring compounds by[3 + 2]cycloaddition reactions ·(2)to construction of optically active quinolinothiopyran compounds by[4 + 2]cycloaddition reactions.Firstly,in this research,the[3 + 2]cycloaddition reactions of ?,a-dicyano compounds with 2,3-indole diketone containing carbonyl group were highly selective used to synthesis chiral indole spirofuran ring compounds.In this compound,two pyrrole rings and a furan ring appear in the form of a spiro ring,providing a method for the synthesis of such compounds in natural product synthesis studies.Quinine-bistrifluoromethyl phenyl thiourea as the catalyst was concerned in this method,product stereotypes were controlled,the diastereoselectivity and enantioselectivity were obtained,and the absolute configuration of the product was determined by Single Crystal X-ray crystallography data analysis.Secondly,we consider the quinine,cinchonine derivatives and other small-molecule organocatalyst that exhibited excellent controllability to catalyze cycloaddition reaction with electron deficient components.Combined with previous work experience,In this paper,two quinine-derived catalysts were studied.Mercaptoquinoline formaldehyde and a-bromo-nitrostyrene as substrates,the quinoline thiopyran compounds with three chiral centers are synthesized efficiently via[4 + 2]cycloaddition reaction.This reaction achieved good non-corresponding selectivity,and better corresponding selectivity.