The crystals of enantiopure SS-[cis-Rh2（Ph2C6H4）2（O2CC2F4CO2）]2（（CH3）2CHCH2NH2）3（1） were obtained from the reaction of S-[cis-Rh2（Ph2C6H4）2（CH3CN）6]BF4（S-2） and（Et4N）2（O2CC2F4CO2） in CH2Cl2/CH3OH u...The crystals of enantiopure SS-[cis-Rh2（Ph2C6H4）2（O2CC2F4CO2）]2（（CH3）2CHCH2NH2）3（1） were obtained from the reaction of S-[cis-Rh2（Ph2C6H4）2（CH3CN）6]BF4（S-2） and（Et4N）2（O2CC2F4CO2） in CH2Cl2/CH3OH under the presence of sec-butyl amine.Compound 1 crystallizes in orthorhombic,space group P212121 with a = 16.880（5）,b = 28.728（9）,c = 20.475（6） ,V = 9929（5） 3,Z = 4,C95H96Cl5F8N3O8.50P4Rh4,Mr = 2280.52,Dc = 1.526 g/cm3,F（000） = 4608 and μ（MoKα） = 0.922 mm-1.The final R = 0.0488 and wR = 0.1164 for 17204 observed reflections with I 〉2σ（I） and R = 0.0814 and wR = 0.1374 for all data with absolute structure parameter =-0.04（3）.Compound 1 contains two inherently chiral S-[cis-Rh2（Ph2C6H4）2] moieties which are connected by two（O2CC2F4CO2） dicarboxylate ligands in the equatorial positions.One of the dirhodium units with Rh-Rh distance of 2.5445（8） is further coordinated by a sec-butyl amine in each axial position.Another dirohdium unit has only one axial sec-butyl amine ligand,and its Rh-Rh distance is 2.5079（9） .展开更多
A chiral supramolecular compound （H3O）{[cis-Rh2（（C6H5）2P（C6H4））2（SO4）- （DMF）]2（μ- OC2H5）}·6C2H5OH （1） has been synthesized and characterized by X-ray single-crystal analysis. Compound 1 crystalli...A chiral supramolecular compound （H3O）{[cis-Rh2（（C6H5）2P（C6H4））2（SO4）- （DMF）]2（μ- OC2H5）}·6C2H5OH （1） has been synthesized and characterized by X-ray single-crystal analysis. Compound 1 crystallizes in monoclinic, space group C2/c with a = 26.752（3）, b = 13.5868（16）, c = 26.611（3） A, β = 103.891（2）°, V= 9389.5（19）A^3, Z = 4, C92H114N2O18P4Rh4, Mr = 2135.49, Dc = 1.511 g/cm^3, F（000） = 4384 and μ（MoKa） = 0.870 mm^-1. The final R = 0.0441 and wR = 0.1186 for 8283 observed reflections with I 〉 2σ（I） and R = 0.0567 and wR = 0.1290 for all data. The structure of the compound is unique. It contains two inherent chiral {c/s-Rh2[（C6H5）2P（C6H4）]2}^2＋ units which are connected not only in the equatorial positions by two sulfato ligands, but also in two of their axial positions by a μ2 ethoxide anion. The remaining axial positions of Rh2^4＋ units in 1 are occupied by the DMF molecules. The sulfato ligands act as P4 tridentate bridges to connect the Rh2^4＋ units. The Rh-Rh metal-metal bond distances are comparable to those in analogous dirhodium compounds.展开更多
The mechanism of Rh（Ⅱ） carbene S-H insertion into H2S in gas phase has been studied by B3LYP functional. Calculation results showed that the Rh（Ⅱ） carbene S-H insertion into H2S took only stepwise channels and n...The mechanism of Rh（Ⅱ） carbene S-H insertion into H2S in gas phase has been studied by B3LYP functional. Calculation results showed that the Rh（Ⅱ） carbene S-H insertion into H2S took only stepwise channels and no concerted channels had been located, which was different from the Rh（Ⅱ） carbene C-H and O-H insertions.展开更多
The mechanisms of insertion of O-H bond of Rh（ Ⅱ ）-methylene carbene into methanol and ethanol were studied by using B3LYP functional both in gas phase and in CH2 C12. The formation of free alcoholic oxonium ylides...The mechanisms of insertion of O-H bond of Rh（ Ⅱ ）-methylene carbene into methanol and ethanol were studied by using B3LYP functional both in gas phase and in CH2 C12. The formation of free alcoholic oxonium ylides is found to be impossible. Alcoholic oxonium ylide are formed as the intermediates before beth the stepwise and the concerted transition states of insertion of O-H bend of Rh（ Ⅱ ）-methylene carbene into methanol and ethanol. With re- gard to the mechanisms of insertion of O-H of Rh（ Ⅱ ） -methylene carbene into alcohols, analysis of the energy bartiers of the two mechanisms indicate that the stepwise mechanism is more plausible than the concerted mechanism.展开更多
Two oxygen adducts of different geometric isomers of the tetrakis（μ-2-anilinopyridinato） dirhodium unit, Rh<sub>2</sub>（ap）<sub>4</sub><sup>+</sup>, have been synthesized and c...Two oxygen adducts of different geometric isomers of the tetrakis（μ-2-anilinopyridinato） dirhodium unit, Rh<sub>2</sub>（ap）<sub>4</sub><sup>+</sup>, have been synthesized and characterized. Rh<sub>2</sub>（ap）<sub>4</sub>O<sub>2</sub>（4,0） is the oxygen adduct 1 of 4, 0 isomer; and Rh<sub>2</sub>（ap）<sub>4</sub>O<sub>2</sub>（2, 2） is the oxygen adduct 2 of 2, 2 isomer. The ESR spectra of both oxygen adducts show that there is a characteristic signal of a superoxide ion, g=2.03. The 4, 0 isomer with different axial ligands gives the order of A<sub>Ⅱ</sub> values; O<sub>2</sub><sup>-</sup>≈ClO<sub>4</sub><sup>-</sup>【Cl<sup>-</sup>【CN<sup>-</sup>. However, the A<sub>Ⅱ</sub> value of the 2, 2 isomer is independent of axial ligands. The half wave potentials E<sub>1/2</sub><sup>1</sup> for different axial ligands are: O<sub>2</sub><sup>-</sup>【Cl<sup>-</sup>【CO, which is consistent with the least A<sub>Ⅱ</sub> value of the superoxide. There are plain differences in electrochemical redox process of the two isomers, that is the 2, 2 trans isomer reacting with oxygen involves reversible oxidation, but the oxygen adduct of the 4, 0 isomer is formed irreversibly. The XPS spectrum of the adduct displays a new peak in the region of展开更多
β,γ-Unsaturated a-diazocarbonyl compounds possess two reactive sites for electrophilic addition-one at the diazo carbon and the other at the vinylogous γ-position.Controlled by catalyst,divergent transformations ar...β,γ-Unsaturated a-diazocarbonyl compounds possess two reactive sites for electrophilic addition-one at the diazo carbon and the other at the vinylogous γ-position.Controlled by catalyst,divergent transformations are achieved starting from the same starting materials,either by Lewis acid-catalyzed addition or by dirhodium-catalyzed metal carbene reactions.In select cases two catalysts working in combination or in sequence provide a relay for cascade transformations.In this review,we summarize advances in catalyst-dependent divergent transformations of β,γ-unsaturated α-diazocarbonyl compounds and highlight the potential of this exciting research area and the many challenges that remain.展开更多
The dirhodium(II)-catalyzed organic reactions,including asymmetric transformation,are significantly benefitted from the discovery of simple and efficient protocols to introduce various bridging ligands,e.g.carboxylic ...The dirhodium(II)-catalyzed organic reactions,including asymmetric transformation,are significantly benefitted from the discovery of simple and efficient protocols to introduce various bridging ligands,e.g.carboxylic acids,amide and phosphoric acids.Ligands lying at axial position of dirhodium(II)complexes could strongly affect the activity and selectivity of these metal complexes involved reactions.This review summarizes the newly explored reactivity of dirhodium(II)complexes with N-heterocyclic carbenes or phosphines as the axial ligands.The asymmetric tries are also highlighted,where their stereo-induction were solely from the axial ligand of dirhodium(II)complexes.In the last part,the reactions catalyzed by inherent chiral ortho-metalated dirhodium(II)/phosphine complexes are also discussed.展开更多
We report the first Rh2(II)-catalyzed asymmetric cycloisomerization of activated enynes to provide cyclopropane-fused tetrahydropyridines in good yields and excellent enantioselectivities under mild conditions.The act...We report the first Rh2(II)-catalyzed asymmetric cycloisomerization of activated enynes to provide cyclopropane-fused tetrahydropyridines in good yields and excellent enantioselectivities under mild conditions.The activated group,CHZ(Z is electronwithdrawing group(EWG)),in the enyne substrates exerts two synergetic roles,one is to activate alkyne for the cyclopropanation reaction;the other is to introduce the C–H…O interaction between substrate and catalyst(reducing the energy barrier of the reaction).This double-mode activation was supported by both density functional theory(DFT)calculations and experimental tests.This strategy was also extended to other CH2 Z(Z can be OH,OMe,F)as activating groups that made the CH2 more acidic so that the substrates could also form increased C–H…O interaction with the catalyst.展开更多
基金Financially supported by the National Natural Science Foundation of China (No. 20973173)
文摘The crystals of enantiopure SS-[cis-Rh2（Ph2C6H4）2（O2CC2F4CO2）]2（（CH3）2CHCH2NH2）3（1） were obtained from the reaction of S-[cis-Rh2（Ph2C6H4）2（CH3CN）6]BF4（S-2） and（Et4N）2（O2CC2F4CO2） in CH2Cl2/CH3OH under the presence of sec-butyl amine.Compound 1 crystallizes in orthorhombic,space group P212121 with a = 16.880（5）,b = 28.728（9）,c = 20.475（6） ,V = 9929（5） 3,Z = 4,C95H96Cl5F8N3O8.50P4Rh4,Mr = 2280.52,Dc = 1.526 g/cm3,F（000） = 4608 and μ（MoKα） = 0.922 mm-1.The final R = 0.0488 and wR = 0.1164 for 17204 observed reflections with I 〉2σ（I） and R = 0.0814 and wR = 0.1374 for all data with absolute structure parameter =-0.04（3）.Compound 1 contains two inherently chiral S-[cis-Rh2（Ph2C6H4）2] moieties which are connected by two（O2CC2F4CO2） dicarboxylate ligands in the equatorial positions.One of the dirhodium units with Rh-Rh distance of 2.5445（8） is further coordinated by a sec-butyl amine in each axial position.Another dirohdium unit has only one axial sec-butyl amine ligand,and its Rh-Rh distance is 2.5079（9） .
基金supported by the National Natural Science Foundation of China (No. 20973173)
文摘A chiral supramolecular compound （H3O）{[cis-Rh2（（C6H5）2P（C6H4））2（SO4）- （DMF）]2（μ- OC2H5）}·6C2H5OH （1） has been synthesized and characterized by X-ray single-crystal analysis. Compound 1 crystallizes in monoclinic, space group C2/c with a = 26.752（3）, b = 13.5868（16）, c = 26.611（3） A, β = 103.891（2）°, V= 9389.5（19）A^3, Z = 4, C92H114N2O18P4Rh4, Mr = 2135.49, Dc = 1.511 g/cm^3, F（000） = 4384 and μ（MoKa） = 0.870 mm^-1. The final R = 0.0441 and wR = 0.1186 for 8283 observed reflections with I 〉 2σ（I） and R = 0.0567 and wR = 0.1290 for all data. The structure of the compound is unique. It contains two inherent chiral {c/s-Rh2[（C6H5）2P（C6H4）]2}^2＋ units which are connected not only in the equatorial positions by two sulfato ligands, but also in two of their axial positions by a μ2 ethoxide anion. The remaining axial positions of Rh2^4＋ units in 1 are occupied by the DMF molecules. The sulfato ligands act as P4 tridentate bridges to connect the Rh2^4＋ units. The Rh-Rh metal-metal bond distances are comparable to those in analogous dirhodium compounds.
文摘The mechanism of Rh（Ⅱ） carbene S-H insertion into H2S in gas phase has been studied by B3LYP functional. Calculation results showed that the Rh（Ⅱ） carbene S-H insertion into H2S took only stepwise channels and no concerted channels had been located, which was different from the Rh（Ⅱ） carbene C-H and O-H insertions.
文摘The mechanisms of insertion of O-H bond of Rh（ Ⅱ ）-methylene carbene into methanol and ethanol were studied by using B3LYP functional both in gas phase and in CH2 C12. The formation of free alcoholic oxonium ylides is found to be impossible. Alcoholic oxonium ylide are formed as the intermediates before beth the stepwise and the concerted transition states of insertion of O-H bend of Rh（ Ⅱ ）-methylene carbene into methanol and ethanol. With re- gard to the mechanisms of insertion of O-H of Rh（ Ⅱ ） -methylene carbene into alcohols, analysis of the energy bartiers of the two mechanisms indicate that the stepwise mechanism is more plausible than the concerted mechanism.
文摘Two oxygen adducts of different geometric isomers of the tetrakis（μ-2-anilinopyridinato） dirhodium unit, Rh<sub>2</sub>（ap）<sub>4</sub><sup>+</sup>, have been synthesized and characterized. Rh<sub>2</sub>（ap）<sub>4</sub>O<sub>2</sub>（4,0） is the oxygen adduct 1 of 4, 0 isomer; and Rh<sub>2</sub>（ap）<sub>4</sub>O<sub>2</sub>（2, 2） is the oxygen adduct 2 of 2, 2 isomer. The ESR spectra of both oxygen adducts show that there is a characteristic signal of a superoxide ion, g=2.03. The 4, 0 isomer with different axial ligands gives the order of A<sub>Ⅱ</sub> values; O<sub>2</sub><sup>-</sup>≈ClO<sub>4</sub><sup>-</sup>【Cl<sup>-</sup>【CN<sup>-</sup>. However, the A<sub>Ⅱ</sub> value of the 2, 2 isomer is independent of axial ligands. The half wave potentials E<sub>1/2</sub><sup>1</sup> for different axial ligands are: O<sub>2</sub><sup>-</sup>【Cl<sup>-</sup>【CO, which is consistent with the least A<sub>Ⅱ</sub> value of the superoxide. There are plain differences in electrochemical redox process of the two isomers, that is the 2, 2 trans isomer reacting with oxygen involves reversible oxidation, but the oxygen adduct of the 4, 0 isomer is formed irreversibly. The XPS spectrum of the adduct displays a new peak in the region of
基金the National Institutes of Health(No.GM 46503)the National Science Foundation(No.CHE-1212446)the starting funding from Soochow University and Key Laboratory of Organic Synthesis of Jiangsu Province
文摘β,γ-Unsaturated a-diazocarbonyl compounds possess two reactive sites for electrophilic addition-one at the diazo carbon and the other at the vinylogous γ-position.Controlled by catalyst,divergent transformations are achieved starting from the same starting materials,either by Lewis acid-catalyzed addition or by dirhodium-catalyzed metal carbene reactions.In select cases two catalysts working in combination or in sequence provide a relay for cascade transformations.In this review,we summarize advances in catalyst-dependent divergent transformations of β,γ-unsaturated α-diazocarbonyl compounds and highlight the potential of this exciting research area and the many challenges that remain.
基金This work was financially supported by the USTC Research Funds of the Double First-Class Initiative(No.YD2060002014)B.H.thanks Minjiang University(Nos.32903602,MJY20019 and MYK21007)Fujian Education Department(No.JT180396)for financial support.
文摘The dirhodium(II)-catalyzed organic reactions,including asymmetric transformation,are significantly benefitted from the discovery of simple and efficient protocols to introduce various bridging ligands,e.g.carboxylic acids,amide and phosphoric acids.Ligands lying at axial position of dirhodium(II)complexes could strongly affect the activity and selectivity of these metal complexes involved reactions.This review summarizes the newly explored reactivity of dirhodium(II)complexes with N-heterocyclic carbenes or phosphines as the axial ligands.The asymmetric tries are also highlighted,where their stereo-induction were solely from the axial ligand of dirhodium(II)complexes.In the last part,the reactions catalyzed by inherent chiral ortho-metalated dirhodium(II)/phosphine complexes are also discussed.
基金the National Natural Science Foundation of China(2187109621672071+7 种基金91856105)the Ministry of Science and Technology of China(2016YFA0602900)the Natural Science Foundation of Guangdong(2018B0303080072018A0303103592016A030310433)the Science and Technology Program of Guangzhou(201707010316)the Fundamental Research Funds for the Central UniversitiesSouth China University of Technology。
文摘We report the first Rh2(II)-catalyzed asymmetric cycloisomerization of activated enynes to provide cyclopropane-fused tetrahydropyridines in good yields and excellent enantioselectivities under mild conditions.The activated group,CHZ(Z is electronwithdrawing group(EWG)),in the enyne substrates exerts two synergetic roles,one is to activate alkyne for the cyclopropanation reaction;the other is to introduce the C–H…O interaction between substrate and catalyst(reducing the energy barrier of the reaction).This double-mode activation was supported by both density functional theory(DFT)calculations and experimental tests.This strategy was also extended to other CH2 Z(Z can be OH,OMe,F)as activating groups that made the CH2 more acidic so that the substrates could also form increased C–H…O interaction with the catalyst.
