Nucleophilic phosphine and amine catalyst-switched chemodivergent[4+1]and[3+3]annulations of allenyl imides andβ,γ-enones have been developed,furnishing highly substituted 2-cyclopentenone and 2-pyranone derivatives...Nucleophilic phosphine and amine catalyst-switched chemodivergent[4+1]and[3+3]annulations of allenyl imides andβ,γ-enones have been developed,furnishing highly substituted 2-cyclopentenone and 2-pyranone derivatives in moderate to excellent yields.Two plausible reaction mechanisms involving two different ketene intermediates have been proposed to explain the observed chemoselectivity.Moreover,by virtue of theα,β-enone substructure of the[4+1]adducts,1,3-dipolar cycloaddition of nitrile imines has been studied in one-pot to provide various fused pyrazoline derivatives.展开更多
Oxazolones are structural subunits in numerous natural products and designed molecules with substantial pharmacological properties.Here,a palladium-catalyzed chemodivergent regio-and enantioselective allylic alkylatio...Oxazolones are structural subunits in numerous natural products and designed molecules with substantial pharmacological properties.Here,a palladium-catalyzed chemodivergent regio-and enantioselective allylic alkylation of 4-or 5-substituted oxazol-2(3H)-ones with Morita-Baylis-Hillman(MBH)adducts has been developed using a spiroketal-based diphosphine as the ligand(50 examples).Interestingly,4-substituted oxazol-2(3H)-ones acted as a C-nucleophiles in the reaction to afford a range of chiral 4,5-substituted oxazol-2(3H)-ones in high yields(72-99%)with good to excellent chemo-,regio-,and enantioselectivities(C/N 95:5->99:1,b/l 91:9->99:1,85-98%ee).When a N-nucleophile was used under otherwise identical conditions,5-substituted oxazol-2(3H)-ones delivered a range of chiral 3,5-substituted oxazol-2(3H)-ones in high yields(68-98%)with good regio-and enantioselectivities(b/l 71:29-91:9,66-94%ee).The synthesis can be readily performed on gram scale under fairly low catalyst loadings,and the utility of the protocol was showcased in the facile transformation of the products into more elaborate chiral molecules.展开更多
Chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines were described,which were established on the basis of either a C—C bond cleavage or a rearrangement process of a reaction inte rmediate.These reactio...Chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines were described,which were established on the basis of either a C—C bond cleavage or a rearrangement process of a reaction inte rmediate.These reactions proceeded in a condition-determined manner with good functional group tolerance.In the first model,2,2-dimethoxyacetaldehyde reacted with aniline to form a new C—N bond,in the presence of O_(2),via a C—C bond cleavage reaction.However,in the second model,by performing the reaction in the absence of O_(2),Heyns rearrangement occurred and generated a new C—O bond to form methyl phenylglycinate.Such condition-determined reactions not only offered the new way for valueadded conversion of biomass-derived platform molecule,2,2-dimethoxyacetaldehyde,but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.展开更多
Four types of unprecedented and chemodivergent reactions betweenα-diketones and alkynylα-diketones have been achieved under the catalysis of phosphine and Br?nsted base,respectively,leading to the rapid construction...Four types of unprecedented and chemodivergent reactions betweenα-diketones and alkynylα-diketones have been achieved under the catalysis of phosphine and Br?nsted base,respectively,leading to the rapid construction of four different classes of biologically important but synthetically challenging molecular scaffolds including 2-hydroxyfuran-3(2H)-ones,4-hydroxy-2-oxabicyclo[2.2.1]heptan-3-ones,1,3-diaryl cyclobutanes,and 4-(furan-2(3H)-ylidene)cyclopent-2-enones.The formation of the products includes two novel rearrangement processes,and further transformations on the products can be easily achieved to deliver value-added substances such as highly functionalized cyclopentanes.Moreover,the 2-hydroxyfuran-3(2H)-one products display promising photophysical properties such as green luminescence under UV light and aggregation-induced emission effect,showing the practical application value of this work.The great potential ofα-diketones in both synthetic chemistry and material science has been unambiguously demonstrated.展开更多
基金the financial support for this investigation from the National Natural Science Foundation of China(No.22072111the Fundamental Research Funds for the Central Universities(No.2023IVA055).
文摘Nucleophilic phosphine and amine catalyst-switched chemodivergent[4+1]and[3+3]annulations of allenyl imides andβ,γ-enones have been developed,furnishing highly substituted 2-cyclopentenone and 2-pyranone derivatives in moderate to excellent yields.Two plausible reaction mechanisms involving two different ketene intermediates have been proposed to explain the observed chemoselectivity.Moreover,by virtue of theα,β-enone substructure of the[4+1]adducts,1,3-dipolar cycloaddition of nitrile imines has been studied in one-pot to provide various fused pyrazoline derivatives.
基金financial supports from the National Key R&D Program of China(grant nos.2022YFA1503702 and 2021YFF0701602)NSFC(grant nos.22231011 and 22271303).
文摘Oxazolones are structural subunits in numerous natural products and designed molecules with substantial pharmacological properties.Here,a palladium-catalyzed chemodivergent regio-and enantioselective allylic alkylation of 4-or 5-substituted oxazol-2(3H)-ones with Morita-Baylis-Hillman(MBH)adducts has been developed using a spiroketal-based diphosphine as the ligand(50 examples).Interestingly,4-substituted oxazol-2(3H)-ones acted as a C-nucleophiles in the reaction to afford a range of chiral 4,5-substituted oxazol-2(3H)-ones in high yields(72-99%)with good to excellent chemo-,regio-,and enantioselectivities(C/N 95:5->99:1,b/l 91:9->99:1,85-98%ee).When a N-nucleophile was used under otherwise identical conditions,5-substituted oxazol-2(3H)-ones delivered a range of chiral 3,5-substituted oxazol-2(3H)-ones in high yields(68-98%)with good regio-and enantioselectivities(b/l 71:29-91:9,66-94%ee).The synthesis can be readily performed on gram scale under fairly low catalyst loadings,and the utility of the protocol was showcased in the facile transformation of the products into more elaborate chiral molecules.
基金the National Natural Science Foundation of China for financial support(Nos.2171101076,21872060 and 21902054)Fundamental Research Funds for the Central Universities(No.2019kfyXJJS072)Natural Science Foundation of Hubei Province(No.2019CFB219)。
文摘Chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines were described,which were established on the basis of either a C—C bond cleavage or a rearrangement process of a reaction inte rmediate.These reactions proceeded in a condition-determined manner with good functional group tolerance.In the first model,2,2-dimethoxyacetaldehyde reacted with aniline to form a new C—N bond,in the presence of O_(2),via a C—C bond cleavage reaction.However,in the second model,by performing the reaction in the absence of O_(2),Heyns rearrangement occurred and generated a new C—O bond to form methyl phenylglycinate.Such condition-determined reactions not only offered the new way for valueadded conversion of biomass-derived platform molecule,2,2-dimethoxyacetaldehyde,but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.
基金This work was supported by the National Natural Science Foundation of China(21871260,22071242)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)+2 种基金Fujian Natural Science Foundation(2018J05035)the China Postdoctoral Science Foundation(2018M630734)the Science and Technology Research Program of the Education Department of Jiangxi Province(GJJ1991151).
文摘Four types of unprecedented and chemodivergent reactions betweenα-diketones and alkynylα-diketones have been achieved under the catalysis of phosphine and Br?nsted base,respectively,leading to the rapid construction of four different classes of biologically important but synthetically challenging molecular scaffolds including 2-hydroxyfuran-3(2H)-ones,4-hydroxy-2-oxabicyclo[2.2.1]heptan-3-ones,1,3-diaryl cyclobutanes,and 4-(furan-2(3H)-ylidene)cyclopent-2-enones.The formation of the products includes two novel rearrangement processes,and further transformations on the products can be easily achieved to deliver value-added substances such as highly functionalized cyclopentanes.Moreover,the 2-hydroxyfuran-3(2H)-one products display promising photophysical properties such as green luminescence under UV light and aggregation-induced emission effect,showing the practical application value of this work.The great potential ofα-diketones in both synthetic chemistry and material science has been unambiguously demonstrated.
