Study On The Photo-Induced Alkylation Reaction Based On The 4-Alkyl-Dihydropyridine

4-alkyl substituted Hantzsch esters could participate in alkyl transfer by C-C bond cleavage under irradiation of the specific wavelength light,was a new type of alkylating reagent.Compared with the traditional metal alkylation reagent,4-alkyl substituted Hantzsch esters have the advantages of easily available,mild reaction conditions,safe and easy to operate.Therefore,4-alkyl substituted Hantzsch was used as alkyl source,under light,the denitroalkylation of?-nitrostyrene and C-H activated alkylation of isoquinoline were studied in this thesis.Section one focuses on photo-induced denitroalkylation of?-nitrostyrenes.Allylic derivatives are important intermediates and widely used in the synthesis of pharmaceuticals,natural products,dyes,and optoelectronic materials.So it is of great significance to explore the synthetic method of allyl derivatives.We chose?-nitrostyrenes as main objects,screening the photocatalyst,oxidant,reaction times and light,and determined the optimal reaction conditions:2.0 equiv 4-alkyl substituted Hantzsch esters,1.5 equiv NaOAc and MeCN as solvent,with the dropwise addition of DTBP?2.0 equiv?in 1 mL MeCN at room temperature under irradiation by a xenon lamp for 12 h.In this section,an efficient and practical approach to the photoinduced denitroalkylation of?-nitrostyrenes in the absence of a metal photocatalyst is demonstrated using readily accessible 4-alkyl substituted Hantzsch esters.Significantly,this photochemical strategy employs DTBP,a widely used inexpensive radical initiator,instead of an expensive metal catalyst to generate the alkyl radical.The simple,economicial and environment-friendly procedure may be applied to the industry in future.Section two focuses on photo-induced C-H activated alkylation of isoquinoline.Isoquinoline alkaloids represent a group of natural products with remarkable importance in the contemporary biomedical research and drug discovery programs.We chose isoquinoline as main objects,screening the acid,reaction times and light,and determined the optimal reaction conditions:2.0 equiv 4-cyclohexyl substituted Hantzsch esters,3.0 equiv CF₃COOH and 1 mL MeCN as solvent at room temperature under irradiation by a xenon lamp for 12 h.This method has the advantages of using cheap and stable raw materials,without metal photocatalyst,mild reaction conditions,safe and easy to operate.