As one of the most essential components in photocuring system,photoinitiators(PIs)exert a crucial influence on the properties of the cured product.However,commercially available PIs encounter challenges in simultaneou...As one of the most essential components in photocuring system,photoinitiators(PIs)exert a crucial influence on the properties of the cured product.However,commercially available PIs encounter challenges in simultaneously achieving efficient photoinitiation performance and excellent light absorption properties,significantly limiting their applications in various fields.Here,two bis-chalcones and four corresponding oxime esters(OXEs)were designed and synthesized as highly efficient PIs.Featuring a structure comprising bis-chalcone and two diphenyl sulfides,the conjugated systems in these compounds enhance their light-absorption properties in near-ultraviolet and visible region,effectively.Both the frontier molecular orbital simulations and excited state calculations suggest the contribution of sulfur atoms to electron delocalization and the formation of conjugated structure.Due to the high reactivity of the N–O bond in OXE moiety,the four OXEs exhibit exceptional free radical photoinitiating ability in commercial acrylic monomers/oligomers with LED@365nm as light source.Notably,one of them demonstrates superior performance in the photoinitiation of multifunctional crosslinker,achieving more than 70%conversion within 3 s,coupled with outstanding absorption at 365 nm.These chalcone-based OXEs are considered to exert significant potential in the realm of free radical photocuring.展开更多
To develop new environmentally friendly fungicides,we designed and synthesized a novel series of D/Lconfigured camphor oxime ester derivatives based on the natural product camphor as a lead compound.We investigated th...To develop new environmentally friendly fungicides,we designed and synthesized a novel series of D/Lconfigured camphor oxime ester derivatives based on the natural product camphor as a lead compound.We investigated the in vitro antifungal activity of these compounds against six common plant pathogenic fungi.Among them,compounds B1-6,B1-17 and B2-6 displayed great in vitro activity against Rhizoctonia solani with EC50 values of 7.28,4.64,and 7.62μg/mL.The HOMO and LUMO calculations indicated that strong electronwithdrawing halogen elements exhibit better activity compared to electron-donating alkyl groups.Preliminary mechanistic studies,using SEM and TEM,indicated that compound B1-17 induced disordered entanglement of hyphae,shrinkage of hyphal surfaces,and vacuole swelling and rupture,which disrupted normal hyphal growth.Additionally,compound B1-17 induced the production and accumulation of ROS,disrupted MMP,and effectively inhibited the germination and formation of sclerotia in Rhizoctonia solani.These compounds hold potential as new antifungal agents for further research.展开更多
An iron-catalyzed coupling reaction of difluoroenol silyl ethers and cyclobutanone oxime esters is described. This protocol provides a convenient access to various previously unknown and potentially useful gem-difluor...An iron-catalyzed coupling reaction of difluoroenol silyl ethers and cyclobutanone oxime esters is described. This protocol provides a convenient access to various previously unknown and potentially useful gem-difluoromethylenated ketonitriles inmoderate to good yields. The transformations of resulting products to other fluorinecontaining products is also documented.展开更多
The synthesis of two new methacrylates such as 2-[(cyclohexylideneamino)oxy]-2-oxoethyl methylacrylate (CHOEMA)and 2-[(cyclopentylideneamino)oxy]-2-oxoethyl methylacrylate(CPOEMA)are described.The monomers produced fr...The synthesis of two new methacrylates such as 2-[(cyclohexylideneamino)oxy]-2-oxoethyl methylacrylate (CHOEMA)and 2-[(cyclopentylideneamino)oxy]-2-oxoethyl methylacrylate(CPOEMA)are described.The monomers produced from the reaction of corresponding cyclohexanone O-(2-chloroacetyl)oxime and cyclopentanone O-(2- chloroacetyl)oxime with sodium methacrylate was polymerized in 1,4-dioxane solution at 65℃using AIBN as an initiator. The monomers and their polymers were characterized by IR,~1H- and ^(13)C-NMR spec...展开更多
Eleven new 1-{5-[4-（benzyloxy）phenyl]-3-methyl-4,5-dihydropyrazol-l-yl} oxime ester dcrivatives were synthesized and characterized by elemental analysis, HRMS, ^1H NMR data. All the compounds were screened for their...Eleven new 1-{5-[4-（benzyloxy）phenyl]-3-methyl-4,5-dihydropyrazol-l-yl} oxime ester dcrivatives were synthesized and characterized by elemental analysis, HRMS, ^1H NMR data. All the compounds were screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results indicate that compounds 8c and 8f possess potent activity with the minimum inhibitory concentrations（MIC） of 1.562--3.125 ug/mL against all the four bacteria. Compounds 8c, 8e and 8f show moderate inhibition against the DNA gyrase（IC50=1.9--2.5 ug/mL）. On the basis of the biological activities, structure-activity relationship was discussed.展开更多
A series of 2,3,4-trimethoxyacetophenoxime esters containing benzothiazole moiety were synthesized by the reaction of oxime with acyl chloride in alkaline medium. Their structures were established by elemental analysi...A series of 2,3,4-trimethoxyacetophenoxime esters containing benzothiazole moiety were synthesized by the reaction of oxime with acyl chloride in alkaline medium. Their structures were established by elemental analysis, IR, and ^1H NMR spectra. The bioassay tests showed that these title compounds exhibit moderate anticancer activity in vitro by MTT method and compounds 6c and 6d could inhibit ERK phosphorylation in NIH 3T3 cell induced by PDGF.展开更多
Comprehensive Summary A general and convenient photoredox-catalyzed acylation and alkylcyanation of MBH acetates has been established,enabling the assembly of the C(sp2)–C(sp3)bond by a nitrogen-centered radical stra...Comprehensive Summary A general and convenient photoredox-catalyzed acylation and alkylcyanation of MBH acetates has been established,enabling the assembly of the C(sp2)–C(sp3)bond by a nitrogen-centered radical strategy for the synthesis of trisubstituted alkenes in moderate to excellent chemical yields(48 examples in total).The reaction of MBH acetates with acyl(indanone)oxime esters afforded trisubstituted alkenes containing 1,4-dicarbonyl groups.Interestingly,the use of Eosin Y as a photocatalyst in the catalytic system resulted in the formation of distal cyano group-anchored trisubstituted alkenes via deconstructive functionalization of cycloketone oxime esters.Notably,these resulting 1,4-dicarbonyl compounds could be applied to late-stage transformations,providing important methods for the synthesis of dihydropyridazin-3(2H)-one.展开更多
The EDA complex-mediated reactions involving oxime esters have been few studied.Herein,an EDA complex formed by thiophenolate anion and oxime ester is reported for photoinduced divergent synthesis of thioethers,depend...The EDA complex-mediated reactions involving oxime esters have been few studied.Herein,an EDA complex formed by thiophenolate anion and oxime ester is reported for photoinduced divergent synthesis of thioethers,depending on different types of oxime esters.Operational simplicity,mild reaction conditions,and flexible options of leaving group demonstrate the generality and synthetic utility of this approach.Such an approach can also enable an interesting thiol-catalysis for the synthesis of phenanthridines.展开更多
Densely functionalized chiral nitrogen-containing heterocycles are ubiquitous in bioactive synthetic compounds and natural products.Herein,we report a nickel(Ni)-catalyzed enantioselective desymmetrizing aza-Heck cycl...Densely functionalized chiral nitrogen-containing heterocycles are ubiquitous in bioactive synthetic compounds and natural products.Herein,we report a nickel(Ni)-catalyzed enantioselective desymmetrizing aza-Heck cyclization of oxime esters with a commercially available chiral pyridinebis(oxazoline)(pybox)ligand.This reaction proceeds under mild reaction conditions,tolerates various functional groups,and leads to chiral 2-substituted-3,7a-dihydro-3aH-indoles.展开更多
Photoinitiators of the oxime ester(OXE)or ketoxime ester(OXE-CO)type can rapidly undergo N—O bond cleavage and generate free radicals to initiate photopolymerization under LED excitation,occupying an important positi...Photoinitiators of the oxime ester(OXE)or ketoxime ester(OXE-CO)type can rapidly undergo N—O bond cleavage and generate free radicals to initiate photopolymerization under LED excitation,occupying an important position in the field of photocuring.However,the commercial OXEs,e.g.,OXE 01 and 02 withλ_(max)'s at 326 and 344 nm,respectively,still do not well match the emission spectra of LEDs.Developing novel OXEs/OXE-COs with high photosensitivity for long-wavelength LEDs has great significance.Here,four new OXEs/OXE-COs with nitro-carbazole-styrene conjugated chromophore were designed,synthesized,and used as photoinitiators.Results demonstrated that all photoinitiators had strong absorption within the UV–vis range(λ_(max):381—392 nm,ε_(max):8200—11500 M^(−1)·cm^(−1)).Molecular design of the oxime ester cleavage to produce a small volume methyl group and a methacryl group with an unsaturated double bond brings high activity and low migration,respectively,in one-photon polymerization under 365—450 nm LEDs excitation.Moreover,OXEs/OXE-COs with PETA exhibited a wide processing window,high resolution(line accuracy~100 nm)and good nano-patterning capability under 780 nm femtosecond laser irradiation in two-photon polymerization,indicating their great potential in 2D/3D microfabrication technologies.展开更多
Pyroptosis is an inflammatory form of programmed cell death with great potential in cancer immunotherapies.Photodynamic therapy(PDT)represents a promising treatment modality to trigger pyroptosis.However,the hypoxic m...Pyroptosis is an inflammatory form of programmed cell death with great potential in cancer immunotherapies.Photodynamic therapy(PDT)represents a promising treatment modality to trigger pyroptosis.However,the hypoxic microenvironment inside the tumors often induces limited therapeutic efficacy.Herein,in this work,the first type of mitochondrial-targeting oxime-ester photogenerator(T-Oximer)was constructed to boost type-I ROS/aryl free radicals which could induce DNA damage by DNA cleaving and facilitate high-efficiency pyroptosis-mediated photoimmunotherapy.Detailed mechanism investigations revealed that T-Oximer could produce aryl free radicals via photolysis reaction and generate type-I ROS(O_(2)^(·-)and·OH)based on the type-I electron transfer process.Meanwhile,T-Oximer could accumulate in the mitochondria,boost mitochondrial radicals,and damage mitochondria in hypoxic tumor cells.Of peculiar interest,T-Oixmer could bind with DNA and cleave DNA to induce DNA damage.Combined mitochondrial damage with DNA cleavage,T-Oximer can initiate pyroptosis,activate the ICD effect,and trigger robust systemic antitumor immunity for efficient tumor regression and metastasis suppression.Our finding provides a new strategy for constructing oxygen-independent photogenerator for high-efficiency pyroptosis-mediated anti-hypoxia photoimmunotherapy.展开更多
基金National Nature Science Foundation of China(Nos.52025032,52103144 and 523B2026)for their financial supportsupported by the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(No.GZC20231544)。
文摘As one of the most essential components in photocuring system,photoinitiators(PIs)exert a crucial influence on the properties of the cured product.However,commercially available PIs encounter challenges in simultaneously achieving efficient photoinitiation performance and excellent light absorption properties,significantly limiting their applications in various fields.Here,two bis-chalcones and four corresponding oxime esters(OXEs)were designed and synthesized as highly efficient PIs.Featuring a structure comprising bis-chalcone and two diphenyl sulfides,the conjugated systems in these compounds enhance their light-absorption properties in near-ultraviolet and visible region,effectively.Both the frontier molecular orbital simulations and excited state calculations suggest the contribution of sulfur atoms to electron delocalization and the formation of conjugated structure.Due to the high reactivity of the N–O bond in OXE moiety,the four OXEs exhibit exceptional free radical photoinitiating ability in commercial acrylic monomers/oligomers with LED@365nm as light source.Notably,one of them demonstrates superior performance in the photoinitiation of multifunctional crosslinker,achieving more than 70%conversion within 3 s,coupled with outstanding absorption at 365 nm.These chalcone-based OXEs are considered to exert significant potential in the realm of free radical photocuring.
基金the Fundamental Research Funds for the Central Universities(KYCYXT2022011,KJYQ2024014)the National Key Research and Development Program of China(2021YFD1700102)for the generous financial support for our programs.
文摘To develop new environmentally friendly fungicides,we designed and synthesized a novel series of D/Lconfigured camphor oxime ester derivatives based on the natural product camphor as a lead compound.We investigated the in vitro antifungal activity of these compounds against six common plant pathogenic fungi.Among them,compounds B1-6,B1-17 and B2-6 displayed great in vitro activity against Rhizoctonia solani with EC50 values of 7.28,4.64,and 7.62μg/mL.The HOMO and LUMO calculations indicated that strong electronwithdrawing halogen elements exhibit better activity compared to electron-donating alkyl groups.Preliminary mechanistic studies,using SEM and TEM,indicated that compound B1-17 induced disordered entanglement of hyphae,shrinkage of hyphal surfaces,and vacuole swelling and rupture,which disrupted normal hyphal growth.Additionally,compound B1-17 induced the production and accumulation of ROS,disrupted MMP,and effectively inhibited the germination and formation of sclerotia in Rhizoctonia solani.These compounds hold potential as new antifungal agents for further research.
基金National Natural Science Foundation of China (Nos.21421002,21991211)the Strategic Priority Research Program of the Chinese Academy of Sciences (No.XDB20000000)。
文摘An iron-catalyzed coupling reaction of difluoroenol silyl ethers and cyclobutanone oxime esters is described. This protocol provides a convenient access to various previously unknown and potentially useful gem-difluoromethylenated ketonitriles inmoderate to good yields. The transformations of resulting products to other fluorinecontaining products is also documented.
基金Afyon Kocatepe Universty Research Fund(No.06-FENED-09)
文摘The synthesis of two new methacrylates such as 2-[(cyclohexylideneamino)oxy]-2-oxoethyl methylacrylate (CHOEMA)and 2-[(cyclopentylideneamino)oxy]-2-oxoethyl methylacrylate(CPOEMA)are described.The monomers produced from the reaction of corresponding cyclohexanone O-(2-chloroacetyl)oxime and cyclopentanone O-(2- chloroacetyl)oxime with sodium methacrylate was polymerized in 1,4-dioxane solution at 65℃using AIBN as an initiator. The monomers and their polymers were characterized by IR,~1H- and ^(13)C-NMR spec...
基金the Student Research Train Project of Anhui University of Technology(No.08021)
文摘Eleven new 1-{5-[4-（benzyloxy）phenyl]-3-methyl-4,5-dihydropyrazol-l-yl} oxime ester dcrivatives were synthesized and characterized by elemental analysis, HRMS, ^1H NMR data. All the compounds were screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results indicate that compounds 8c and 8f possess potent activity with the minimum inhibitory concentrations（MIC） of 1.562--3.125 ug/mL against all the four bacteria. Compounds 8c, 8e and 8f show moderate inhibition against the DNA gyrase（IC50=1.9--2.5 ug/mL）. On the basis of the biological activities, structure-activity relationship was discussed.
基金Project supported by the National Key Project for Basic Research （No.2003CB114404）, High-tech Research and Development Program of China （No. 2002AA217131）, the National Natural Science Foundation of China （Nos. 20442003 and 20362004） and Program for New Century Excellent Talents in University of China （No. NCET-04-0912）.
文摘A series of 2,3,4-trimethoxyacetophenoxime esters containing benzothiazole moiety were synthesized by the reaction of oxime with acyl chloride in alkaline medium. Their structures were established by elemental analysis, IR, and ^1H NMR spectra. The bioassay tests showed that these title compounds exhibit moderate anticancer activity in vitro by MTT method and compounds 6c and 6d could inhibit ERK phosphorylation in NIH 3T3 cell induced by PDGF.
基金the school level research projects of Changzhou University(No.ZMF23020007).
文摘Comprehensive Summary A general and convenient photoredox-catalyzed acylation and alkylcyanation of MBH acetates has been established,enabling the assembly of the C(sp2)–C(sp3)bond by a nitrogen-centered radical strategy for the synthesis of trisubstituted alkenes in moderate to excellent chemical yields(48 examples in total).The reaction of MBH acetates with acyl(indanone)oxime esters afforded trisubstituted alkenes containing 1,4-dicarbonyl groups.Interestingly,the use of Eosin Y as a photocatalyst in the catalytic system resulted in the formation of distal cyano group-anchored trisubstituted alkenes via deconstructive functionalization of cycloketone oxime esters.Notably,these resulting 1,4-dicarbonyl compounds could be applied to late-stage transformations,providing important methods for the synthesis of dihydropyridazin-3(2H)-one.
基金support from the National Natural Science Foundation of China(22171177)the Guangdong-Hong Kong Joint Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province(2023B1212120011)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(2023A1515110791)the Chemistry and Chemical Engineering Guangdong Laboratory(2312002)the Guangdong Major Project of Basic and Applied Basic Research(2019B030302009)the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme 2019(GDUPS2019).
文摘The EDA complex-mediated reactions involving oxime esters have been few studied.Herein,an EDA complex formed by thiophenolate anion and oxime ester is reported for photoinduced divergent synthesis of thioethers,depending on different types of oxime esters.Operational simplicity,mild reaction conditions,and flexible options of leaving group demonstrate the generality and synthetic utility of this approach.Such an approach can also enable an interesting thiol-catalysis for the synthesis of phenanthridines.
基金The authors are grateful for financial support from the Chinese Academy of Science(grant no.XDB20020000)the National Natural Science Foundation of China(no.21933004)+2 种基金the Shenzhen STIC(nos.JCYJ20170412150507046 and JCYJ20170412150343516)the Shenzhen San-Ming Project(no.SZSM201809085)fellowship from the International Postdoctoral Exchange Fellowship Program(no.2020014 to H.C.Shen).
文摘Densely functionalized chiral nitrogen-containing heterocycles are ubiquitous in bioactive synthetic compounds and natural products.Herein,we report a nickel(Ni)-catalyzed enantioselective desymmetrizing aza-Heck cyclization of oxime esters with a commercially available chiral pyridinebis(oxazoline)(pybox)ligand.This reaction proceeds under mild reaction conditions,tolerates various functional groups,and leads to chiral 2-substituted-3,7a-dihydro-3aH-indoles.
基金supported by the National Natural Science Foundation of China(51873154)the"Pioneer"and"Leading Goose"R&D program of Zhejiang Province(2023C01186).
文摘Photoinitiators of the oxime ester(OXE)or ketoxime ester(OXE-CO)type can rapidly undergo N—O bond cleavage and generate free radicals to initiate photopolymerization under LED excitation,occupying an important position in the field of photocuring.However,the commercial OXEs,e.g.,OXE 01 and 02 withλ_(max)'s at 326 and 344 nm,respectively,still do not well match the emission spectra of LEDs.Developing novel OXEs/OXE-COs with high photosensitivity for long-wavelength LEDs has great significance.Here,four new OXEs/OXE-COs with nitro-carbazole-styrene conjugated chromophore were designed,synthesized,and used as photoinitiators.Results demonstrated that all photoinitiators had strong absorption within the UV–vis range(λ_(max):381—392 nm,ε_(max):8200—11500 M^(−1)·cm^(−1)).Molecular design of the oxime ester cleavage to produce a small volume methyl group and a methacryl group with an unsaturated double bond brings high activity and low migration,respectively,in one-photon polymerization under 365—450 nm LEDs excitation.Moreover,OXEs/OXE-COs with PETA exhibited a wide processing window,high resolution(line accuracy~100 nm)and good nano-patterning capability under 780 nm femtosecond laser irradiation in two-photon polymerization,indicating their great potential in 2D/3D microfabrication technologies.
基金partially funded by the National Natural Science Foundation of China(No.22308192)the Guangdong Provincial Special Support Program for Prominent Talents(2021JC06Y656)+1 种基金the Natural Science Foundation of Guangdong Province,China(No.2023A1515012934)Guangdong Province Marine Economic Development Project(No.GDNRC[2024]27).
文摘Pyroptosis is an inflammatory form of programmed cell death with great potential in cancer immunotherapies.Photodynamic therapy(PDT)represents a promising treatment modality to trigger pyroptosis.However,the hypoxic microenvironment inside the tumors often induces limited therapeutic efficacy.Herein,in this work,the first type of mitochondrial-targeting oxime-ester photogenerator(T-Oximer)was constructed to boost type-I ROS/aryl free radicals which could induce DNA damage by DNA cleaving and facilitate high-efficiency pyroptosis-mediated photoimmunotherapy.Detailed mechanism investigations revealed that T-Oximer could produce aryl free radicals via photolysis reaction and generate type-I ROS(O_(2)^(·-)and·OH)based on the type-I electron transfer process.Meanwhile,T-Oximer could accumulate in the mitochondria,boost mitochondrial radicals,and damage mitochondria in hypoxic tumor cells.Of peculiar interest,T-Oixmer could bind with DNA and cleave DNA to induce DNA damage.Combined mitochondrial damage with DNA cleavage,T-Oximer can initiate pyroptosis,activate the ICD effect,and trigger robust systemic antitumor immunity for efficient tumor regression and metastasis suppression.Our finding provides a new strategy for constructing oxygen-independent photogenerator for high-efficiency pyroptosis-mediated anti-hypoxia photoimmunotherapy.
