Polyhydroxy enyne compound (+)-(1'S, 2R, 3S, 5S, 6S)-5,6-dimethoxy-5, 6-dimethyl- 2-(1'-hydroxylpropyl-2-ne)-3-vinyl-l,4-dioxane has been synthesized from D-(-)-tartaric acid. A new chiral center was establ...Polyhydroxy enyne compound (+)-(1'S, 2R, 3S, 5S, 6S)-5,6-dimethoxy-5, 6-dimethyl- 2-(1'-hydroxylpropyl-2-ne)-3-vinyl-l,4-dioxane has been synthesized from D-(-)-tartaric acid. A new chiral center was established by nucleophilic addition with 87% de. The modified Mosher's method was employed to confirm the absolute configuration of 17, which assigned the S-configuration at the new chiral center.展开更多
A regiodivergent hydrophosphorylation of enynes with phosphites has been developed using earthabundant nickel catalyst.The manipulation of regioselectivity can be achieved by regulating the insertion order of alkyne b...A regiodivergent hydrophosphorylation of enynes with phosphites has been developed using earthabundant nickel catalyst.The manipulation of regioselectivity can be achieved by regulating the insertion order of alkyne bonds with(RO)_(2)P(O)-Ni-H or R_(2)P(O)O-Ni-H species,respectively.Under the Ni/Xantphos catalysis,4,1-hydrophosphorylation is selectively obtained while the adding of acid can promote reactions towards 1,2-addition.By employing an additional Pd-H catalysis,2,1-hydrophosphorylation is also an accessible task in one-pot reaction.Mechanistic studies and analysis have also been performed to interpret the origin of the regioselective regulation.This work highlights the arts in accessing different regioisomers by diverting common elementary reaction steps.展开更多
An efficient and cost-effective method for the preparation of fluorinated conjugated enynes was described, tile method was compatible with a variety of functional groups such as chloride, amine, cyano and ester group....An efficient and cost-effective method for the preparation of fluorinated conjugated enynes was described, tile method was compatible with a variety of functional groups such as chloride, amine, cyano and ester group. The method could also be extended to the coupling of (R,Z)-3-(2-chloro-1,2-difluorovinyl)-4-alkyloxazolidin-2-one (3) with moderate yields.展开更多
Hybrid quantum mechanics/molecular mechanics calculations were performed to elucidate how[Mn^(Ⅲ)porphyrin]^(+X−)-based metal-organic frameworks(MOFs)catalyze the[2+1]cycloisomerization of enynes and why zwitterionic ...Hybrid quantum mechanics/molecular mechanics calculations were performed to elucidate how[Mn^(Ⅲ)porphyrin]^(+X−)-based metal-organic frameworks(MOFs)catalyze the[2+1]cycloisomerization of enynes and why zwitterionic MOFs exhibit strong activity in Lewis acid catalysis.The calculations showed that zwitterionic MOFs have a“pure cationic active center”leading to a concerted nucleophilic attack pathway with lower barriers.In contrast,metals with coordinating anions have reduced electrophilicity,resulting in a stepwise radical-type pathway with much higher barriers.Further calculations showed the nature of catalysis was strongly depended on the charge on the anion ligand.A good linear relationship between the NPA charge and barrier was found,and verified by 73 anions with small derivations,which presents a universal adaptive character for various coordinated anions.展开更多
Aryl sulfonyl radical triggered cascade cyclization of phenyl-linked 1,6-enynes for the synthesis of biologically important indenes containing alkenyl C—X bonds and 10a,11-dihydro-10H-benzo[b]fluorines is presented.I...Aryl sulfonyl radical triggered cascade cyclization of phenyl-linked 1,6-enynes for the synthesis of biologically important indenes containing alkenyl C—X bonds and 10a,11-dihydro-10H-benzo[b]fluorines is presented.In these radical cascade processes,three new chemical bonds,including C—S,C—C,and C—X bonds,and three C—C bonds are formed in one step.The method is attractive and valuable due to its metal-free,mild reaction conditions,broad substrate scope and good functional group tolerance.展开更多
Catalytic diastereodivergent hydrosilylative enyne cyclization with high generality and broad scope was achieved using electronic ac-tivated N-heterocyclic carbene-Ni(O)as a catalyst and R_(3)SiH as silane(IPr^(Cl),sy...Catalytic diastereodivergent hydrosilylative enyne cyclization with high generality and broad scope was achieved using electronic ac-tivated N-heterocyclic carbene-Ni(O)as a catalyst and R_(3)SiH as silane(IPr^(Cl),syn-:anti-selectivity from up to 98:2 to 7:93 by Z=0,NH vs.NMs,R^(1)=n-pentyl).Heterocycles bearing homoallylsilane rather than vinylsilane was obtained chemoselectively.The undesired yet highly competitive reactivity was suppressed,like direct hydrosilylation of alkene and alkyne concurrently.Optionally,the homoallylsilane products could be reduced further in one-pot using IPr^(Me) as ligand and(EtO)_(3)SiH as silane under otherwise the same standard condition as the above,offering practical access to additional stereocenters and more diverse product structures from enynes.展开更多
One of the largest subfamilies within the famous Daphniphyllum alkaloid family is made up of the yuzurimine-type(or macrodaphniphyllamine-type) alkaloids. Their complex aza-polycyclic caged structures, several contigu...One of the largest subfamilies within the famous Daphniphyllum alkaloid family is made up of the yuzurimine-type(or macrodaphniphyllamine-type) alkaloids. Their complex aza-polycyclic caged structures, several contiguous stereogenic centers, and vicinal all-carbon quaternary centers make these alkaloids formidable challenge for synthetic chemists. Recently, synthesis of these alkaloids has received extensive attention from our community. Herein, we wish to report the total synthesis of C_(14)–epideoxycalyciphylline H, a putative member of yuzurimine-type alkaloid subfamily. Key transformations employed in our approach include an intramolecular Prins reaction and a Pd-catalyzed enyne cycloisomerization. In addition, synthesis of a daphnezomine L-type alkaloid, paxdaphnidine A, was also studied.展开更多
Herein,copper-catalyzed 1,4-protosilylation and 1,4-protoborylation of enynic orthoesters have been developed.The enynic orthoesters as precursors of unstable enynic esters were applied to produce the functionalized 2...Herein,copper-catalyzed 1,4-protosilylation and 1,4-protoborylation of enynic orthoesters have been developed.The enynic orthoesters as precursors of unstable enynic esters were applied to produce the functionalized 2,3-allenoate products.Meanwhile,the asymmetric 1,4-protosilylation of enynic orthoesters with Ph Me2Si-Bpin was also studied.The chiral monopyridine imidazoline ligand was efficient to provide the asymmetric 1,4-protosilylation products with high enantioselectivity.展开更多
Palladium (II) catalyzed reactions of allyl propynoate in the presence of excess halide ions with or without allyl halide or acrolein were studied, yielding (E)-3-halo-2-allyl-acrylic acid as the sole product. A mecha...Palladium (II) catalyzed reactions of allyl propynoate in the presence of excess halide ions with or without allyl halide or acrolein were studied, yielding (E)-3-halo-2-allyl-acrylic acid as the sole product. A mechanism involving halopalladation, carbopalladation, ring opening and β-heteroatom elimination was proposed and was further justified by the reaction with deuterated substrate.展开更多
文摘Polyhydroxy enyne compound (+)-(1'S, 2R, 3S, 5S, 6S)-5,6-dimethoxy-5, 6-dimethyl- 2-(1'-hydroxylpropyl-2-ne)-3-vinyl-l,4-dioxane has been synthesized from D-(-)-tartaric acid. A new chiral center was established by nucleophilic addition with 87% de. The modified Mosher's method was employed to confirm the absolute configuration of 17, which assigned the S-configuration at the new chiral center.
基金Financial support from Dalian Outstanding Young Scientific Talent(No.2020RJ05)the National Natural Science Foundation of China(Nos.22071239,21971234)。
文摘A regiodivergent hydrophosphorylation of enynes with phosphites has been developed using earthabundant nickel catalyst.The manipulation of regioselectivity can be achieved by regulating the insertion order of alkyne bonds with(RO)_(2)P(O)-Ni-H or R_(2)P(O)O-Ni-H species,respectively.Under the Ni/Xantphos catalysis,4,1-hydrophosphorylation is selectively obtained while the adding of acid can promote reactions towards 1,2-addition.By employing an additional Pd-H catalysis,2,1-hydrophosphorylation is also an accessible task in one-pot reaction.Mechanistic studies and analysis have also been performed to interpret the origin of the regioselective regulation.This work highlights the arts in accessing different regioisomers by diverting common elementary reaction steps.
基金Acknowledgement The authors gratefully acknowledge the financial support from National Basic Research Program of China (Nos. 2012CB821600, 2010CB126103), the Key Program of Natural Science Foundation of China (No.21032006), National Natural Science Foundation of China (Nos. 21172245, 21172244, B020304), Agroscientific Research in the Public Interest (No. 201103007), the National Key Technologies R&D Program (No. 2011BAE06B05), Shanghai Scientific Research Program (No. 10XD1405200), and SIOC.
文摘An efficient and cost-effective method for the preparation of fluorinated conjugated enynes was described, tile method was compatible with a variety of functional groups such as chloride, amine, cyano and ester group. The method could also be extended to the coupling of (R,Z)-3-(2-chloro-1,2-difluorovinyl)-4-alkyloxazolidin-2-one (3) with moderate yields.
基金supported by the National Natural Science Foundation of China (Nos. 21822303 21772020 22173083)Program for Science Technology Innovation Talents in Universities of Henan Province (No. 20HASTIT004)the support from the Henan Province Supercomputing Center
文摘Hybrid quantum mechanics/molecular mechanics calculations were performed to elucidate how[Mn^(Ⅲ)porphyrin]^(+X−)-based metal-organic frameworks(MOFs)catalyze the[2+1]cycloisomerization of enynes and why zwitterionic MOFs exhibit strong activity in Lewis acid catalysis.The calculations showed that zwitterionic MOFs have a“pure cationic active center”leading to a concerted nucleophilic attack pathway with lower barriers.In contrast,metals with coordinating anions have reduced electrophilicity,resulting in a stepwise radical-type pathway with much higher barriers.Further calculations showed the nature of catalysis was strongly depended on the charge on the anion ligand.A good linear relationship between the NPA charge and barrier was found,and verified by 73 anions with small derivations,which presents a universal adaptive character for various coordinated anions.
基金the National Natural Science Foundation of China(No.21861043)the Yunnan Fundamental Research Projects(No.2019FB016)Scientific and Technological Innovation Team of Optical Functional Materials of Yunnan Provincial Education Department forfinancial support.
文摘Aryl sulfonyl radical triggered cascade cyclization of phenyl-linked 1,6-enynes for the synthesis of biologically important indenes containing alkenyl C—X bonds and 10a,11-dihydro-10H-benzo[b]fluorines is presented.In these radical cascade processes,three new chemical bonds,including C—S,C—C,and C—X bonds,and three C—C bonds are formed in one step.The method is attractive and valuable due to its metal-free,mild reaction conditions,broad substrate scope and good functional group tolerance.
基金the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)NSFC(No.22071096)SUSTech(Nos.Y01501808 and Y01506014).
文摘Catalytic diastereodivergent hydrosilylative enyne cyclization with high generality and broad scope was achieved using electronic ac-tivated N-heterocyclic carbene-Ni(O)as a catalyst and R_(3)SiH as silane(IPr^(Cl),syn-:anti-selectivity from up to 98:2 to 7:93 by Z=0,NH vs.NMs,R^(1)=n-pentyl).Heterocycles bearing homoallylsilane rather than vinylsilane was obtained chemoselectively.The undesired yet highly competitive reactivity was suppressed,like direct hydrosilylation of alkene and alkyne concurrently.Optionally,the homoallylsilane products could be reduced further in one-pot using IPr^(Me) as ligand and(EtO)_(3)SiH as silane under otherwise the same standard condition as the above,offering practical access to additional stereocenters and more diverse product structures from enynes.
基金the National Natural Science Foundation of China (Nos.21971104 and 22271136)Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis (No.ZDSYS20190902093215877)+4 种基金Guangdong Provincial Key Laboratory of Catalysis (No.2020B121201002)Guangdong Innovative Program (No.2019BT02Y335)Education Department of Guangdong Province, Key research projects in colleges and universities in Guangdong Province (No.2021ZDZX2035)Shenzhen Nobel Prize Scientists Laboratory Project (No.C17783101)Innovative Team of Universities in Guangdong Province (No.2020KCXTD016)。
文摘One of the largest subfamilies within the famous Daphniphyllum alkaloid family is made up of the yuzurimine-type(or macrodaphniphyllamine-type) alkaloids. Their complex aza-polycyclic caged structures, several contiguous stereogenic centers, and vicinal all-carbon quaternary centers make these alkaloids formidable challenge for synthetic chemists. Recently, synthesis of these alkaloids has received extensive attention from our community. Herein, we wish to report the total synthesis of C_(14)–epideoxycalyciphylline H, a putative member of yuzurimine-type alkaloid subfamily. Key transformations employed in our approach include an intramolecular Prins reaction and a Pd-catalyzed enyne cycloisomerization. In addition, synthesis of a daphnezomine L-type alkaloid, paxdaphnidine A, was also studied.
基金the funding support of the National Natural Science Foundation of China(No.21871240)the Strategic Priority Research Program of the CAS(No.XDPB14)the Fundamental Research Funds for the Central Universities(No.WK2060190082)。
文摘Herein,copper-catalyzed 1,4-protosilylation and 1,4-protoborylation of enynic orthoesters have been developed.The enynic orthoesters as precursors of unstable enynic esters were applied to produce the functionalized 2,3-allenoate products.Meanwhile,the asymmetric 1,4-protosilylation of enynic orthoesters with Ph Me2Si-Bpin was also studied.The chiral monopyridine imidazoline ligand was efficient to provide the asymmetric 1,4-protosilylation products with high enantioselectivity.
基金theMajorStateBasicResearchDevelopmentProgramofChina (No .G2 0 0 0 0 775 0 2 A) ,andtheNationalNaturalScienceFoundationofChina (No.2 0 0 72 0 45 )
文摘Palladium (II) catalyzed reactions of allyl propynoate in the presence of excess halide ions with or without allyl halide or acrolein were studied, yielding (E)-3-halo-2-allyl-acrylic acid as the sole product. A mechanism involving halopalladation, carbopalladation, ring opening and β-heteroatom elimination was proposed and was further justified by the reaction with deuterated substrate.