Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized ...Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized by installing NHPIEs along the TX backbone and characterized.The investigated TX-NHPIEs have a 60 nm redshift and demonstrate sterling initiating efficiency for free radical photopolymerization(FRP)under LED@450 nm light irradiation compared with the commercialized isopropylthioxanthone(ITX).Real-time1Hnuclear magnetic resonance(1H NMR),electron spin resonance(ESR),decarboxylation and gas chromatograph-mass spectrometer(GC–MS)experiments and density functional theory(DFT)reveal that TX-NHPIEs can generate one alkyl radical and one N-centered iminyl radical,which can initiate FRP directly and indirectly,respectively.In other words,TX-NHPIEs absorb one photon and can generate two active radicals,which break through the limitations of common PIs.TX-NHPIE-Cpe demonstrates the highest initiating efficiency,and its application in coatings and 3D printing was also studied,indicating TX-NHPIEs have broad potential applications in photopolymerization processes.展开更多
An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist o...An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions and excellent substrate generality give this protocol broad application prospects.展开更多
Comprehensive Summary A visible-light-induced decarboxylative radical cascade cyclization reaction between N-(2-cyanoaryl)-acrylamides and alkyl N-(acyloxy)phthalimide(NHPI esters)for the construction of phenanthridin...Comprehensive Summary A visible-light-induced decarboxylative radical cascade cyclization reaction between N-(2-cyanoaryl)-acrylamides and alkyl N-(acyloxy)phthalimide(NHPI esters)for the construction of phenanthridine derivatives has been developed.This approach utilizes lithium iodide(LiI)and triphenylphosphine(PPh_(3))as the redox catalysts and the alkyl radical is produced through the photoactivation of the electron donor-acceptor(EDA)complex.A series of primary,secondary,and tertiary alkyl-substituted phenanthridines are prepared in up to 82%yield without transition-metal catalysts,chemical oxidants,or metal-/organic dye-based photocatalysts.展开更多
基金the financial support by the National Natural Science Foundation of China(Nos.22301107,52373057)the Nature Science Foundation of Jiangsu Province(No.BK20200610)+1 种基金the Fundamental Research Funds for the Central Universities(No.JUSRP122021)Jiangsu Province"Innovation and Entrepreneurship Doctor"Talent Plan(No.JSSCBS20221053)also provided support。
文摘Developing efficient and long wavelength sensitive unimolecular photoinitiators(PIs)is still facing a great challenge.In this work,a series of thioxanthone-based N-hydroxyphthalimide esters(TX-NHPIEs)were synthesized by installing NHPIEs along the TX backbone and characterized.The investigated TX-NHPIEs have a 60 nm redshift and demonstrate sterling initiating efficiency for free radical photopolymerization(FRP)under LED@450 nm light irradiation compared with the commercialized isopropylthioxanthone(ITX).Real-time1Hnuclear magnetic resonance(1H NMR),electron spin resonance(ESR),decarboxylation and gas chromatograph-mass spectrometer(GC–MS)experiments and density functional theory(DFT)reveal that TX-NHPIEs can generate one alkyl radical and one N-centered iminyl radical,which can initiate FRP directly and indirectly,respectively.In other words,TX-NHPIEs absorb one photon and can generate two active radicals,which break through the limitations of common PIs.TX-NHPIE-Cpe demonstrates the highest initiating efficiency,and its application in coatings and 3D printing was also studied,indicating TX-NHPIEs have broad potential applications in photopolymerization processes.
基金supported by the National Natural Science Foundation of China (No. 22078299)Zhejiang Provincial Natural Science Foundation of China (Nos. LY21B060005, LQ20B060007)+1 种基金the College of Pharmaceutical Sciences, Zhejiang University of TechnologyCollaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals for the financial help。
文摘An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions and excellent substrate generality give this protocol broad application prospects.
基金supported by the National Natural Science Foundation of China(22078084)the Scientific Research Fund of Hunan Provincial Education Department(22B0674)the Science and Natural Science Foundation of Hunan Province(Nos.2023J30273 and 2023J40301).
文摘Comprehensive Summary A visible-light-induced decarboxylative radical cascade cyclization reaction between N-(2-cyanoaryl)-acrylamides and alkyl N-(acyloxy)phthalimide(NHPI esters)for the construction of phenanthridine derivatives has been developed.This approach utilizes lithium iodide(LiI)and triphenylphosphine(PPh_(3))as the redox catalysts and the alkyl radical is produced through the photoactivation of the electron donor-acceptor(EDA)complex.A series of primary,secondary,and tertiary alkyl-substituted phenanthridines are prepared in up to 82%yield without transition-metal catalysts,chemical oxidants,or metal-/organic dye-based photocatalysts.
