36634-63-6Relevant academic research and scientific papers
Blue light-promoted cyclopropenizations of N-tosylhydrazones in water
Yan, Kaichuan,He, Hua,Li, Jianglian,Luo, Yi,Lai, Ruizhi,Guo, Li,Wu, Yong
supporting information, p. 3984 - 3987 (2021/06/15)
Carbene transfer reactions play an important role in the field of organic synthesis because of their ability to construct a variety of molecules. Herein, we reported on blue light-induced cyclopropenizations of N-tosylhydrazones in water, which avoids the use of expensive metal-based catalysts and toxic organic solvents. This metal-free and operationally simple methodology enable highly efficient cyclopropenizations, X-H insertion reactions, and cyclopropanation under mild reaction conditions.
Blue Light-promoted Carbene Transfer Reactions of Tosylhydrazones
Xu, Yingying,Lv, Guanghui,Yan, Kaichuan,He, Hua,Li, Jianglian,Luo, Yi,Lai, Ruizhi,Hai, Li,Wu, Yong
supporting information, p. 1945 - 1947 (2020/06/08)
Metal-free photochemical carbene-transfer reactions of tosylhydrazones were developed under blue light irradiation at room temperature. This reaction constructs C?X (X=C, N, O, S) bonds and cyclopropanes from readily available and stable starting material
Blue light-promoted N–H insertion of amides, isatins, sulfonamides and imides into aryldiazoacetates: Synthesis of unnatural α-aryl amino acid derivatives
Okada, Celso Y.,dos Santos, Caio Y.,Jurberg, Igor D.
, (2020/07/03)
A photochemical protocol using blue light allows the N–H insertion of amides, isatins, sulfonamides and imides into aryldiazoacetates to afford the corresponding α-amino esters. This method is experimentally simple, inexpensive and tolerates numerous functional groups, thus allowing the straightforward preparation of a variety of α-aryl amino acid derivatives in good yields.
Synthesis of Chiral Bifunctional NHC Ligands and Survey of Their Utilities in Asymmetric Gold Catalysis
Liu, Yunkui,Wang, Xing-Wang,Zhang, Jun-Qi,Zhang, Liming
supporting information, (2019/08/26)
The synthesis and characterization of the chiral bifunctional NHC ligands based on the imidazo[1,5-a]pyridine (ImPy) scaffold are described. These ligands possess a fluxional biaryl axis and a chiral center. The configurational stability of the biaryl axis in their gold(I) complexes is investigated. The application of these axially chiral ImPy-based AuCl complexes in a series of gold catalysis is explored, and varying degrees of asymmetric induction are observed. In most cases, the ligand (aS,R)-L8-H with its cyclohexyl group pointing to the reaction site and hence exerting asymmetric steric influence is more effective in asymmetric induction.
Bis(imino)pyridine iron complexes for catalytic carbene transfer reactions
Wang, Ban,Howard, Isaac G.,Pope, Jackson W.,Conte, Eric D.,Deng, Yongming
, p. 7958 - 7963 (2019/09/06)
The bis(imino)pyridine iron complex, for the first time, is developed as an effective metal carbene catalyst for carbene transfer reactions of donor-acceptor diazo compounds. Its broad catalytic capability is demonstrated by a range of metal carbene reactions, from cyclopropanation, cyclopropenation, epoxidation, and Doyle-Kirmse reaction to O-H insertion, N-H insertion, and C-H insertion reactions. The asymmetric cyclopropanation of styrene and methyl phenyldiazoacetate was successfully achieved by the new chiral bis(imino)pyridine iron catalyst, which delivers a new gateway for the development of chiral iron catalysis for metal carbene reactions.
An artificial metalloenzyme for carbene transfer based on a biotinylated dirhodium anchored within streptavidin
Zhao, Jingming,Bachmann, Daniel G.,Lenz, Markus,Gillingham, Dennis G.,Ward, Thomas R.
, p. 2294 - 2298 (2018/05/23)
We report on artificial metalloenzymes that incorporate a biotinylated dirhodium core embedded within engineered streptavidin (Sav hereafter) variants. The resulting biohybrid catalyzes the carbene insertion in C-H bonds and olefins. Chemical- and genetic optimization allows to modulate the catalytic activity of the artificial metalloenzymes that are shown to be active in the periplasm of E. coli (up to 20 turnovers).
Design and Synthesis of Novel Chiral Dirhodium(II) Carboxylate Complexes for Asymmetric Cyclopropanation Reactions
Adly, Frady G.,Gardiner, Michael G.,Ghanem, Ashraf
, p. 3447 - 3461 (2016/03/05)
A novel approach to the design of dirhodium(II) tetracarboxylates derived from (S)-amino acid ligands is reported. The approach is founded on tailoring the steric influences of the overall catalyst structure by reducing the local symmetry of the ligand's N-heterocyclic tether. The application of the new approach has led to the uncovering of [Rh2(S-tertPTTL)4] as a new member of the dirhodium(II) family with extraordinary selectivity in cyclopropanation reactions. The stereoselectivity of [Rh2(S-tertPTTL)4] was found to be comparable to that of [Rh2(S-PTAD)4] (up to >99 % ee), with the extra benefit of being more synthetically accessible. Correlations based on X-ray structures to justify the observed enantioinduction are also discussed.
Highly Regio- and Enantioselective Formal [3 + 2]-Annulation of Indoles with Electrophilic Enol Carbene Intermediates
Jing, Changcheng,Cheng, Qing-Qing,Deng, Yongming,Arman, Hadi,Doyle, Michael P.
supporting information, p. 4550 - 4553 (2016/09/28)
Chiral cyclopentane-fused indolines are synthesized with high regio- and enantiocontrol by formal [3 + 2]-annulation reactions of indoles and electrophilic enol carbenes. High enantioselectivity and exclusive regiocontrol occurred with enoldiazoacetamides using a less sterically encumbered prolinate-ligated dirhodium(II) catalyst in reactions with N-substituted indoles without substituents at the 2- or 3-positions via a selective vinylogous addition process. In this transformation, donor-acceptor cyclopropenes generated from enoldiazoacetamides serve as the carbene precursors to form metal carbene intermediates.
Homochiral coordination cages assembled from dinuclear paddlewheel nodes and enantiopure ditopic ligands: Syntheses, structures and catalysis
Chen, Lianfen,Kang, Jian,Cui, Hao,Wang, Yingxia,Liu, Lan,Zhang, Li,Su, Cheng-Yong
supporting information, p. 12180 - 12188 (2016/01/15)
A series of homochiral metal-organic cages (MOCs) have been obtained from self-assembly of Cu(ii) salts with chiral N,N′-(bicyclo[2,2,2]oct-7-ene-tetracarboxylic)-bis-amino acids. Single-crystal X-ray diffraction analyses reveal that these compounds show a lantern-type cage structure, in which one pair of Cu2(CO2)4 paddlewheels is linked by four diacid ligands. The resulting homochiral cages have been fully characterized by EA, TOF-MS, TGA, VTPXRD, IR, UV, and CD measurements. The catalytic tests reveal that these Cu(ii) cages are effective in cyclopropanation with excellent diastereoselectivity (up to 99:1 E/Z). In addition, the cage catalysts can promote the aziridination reaction with PhI = NNs.
Enantioselective dirhodium(II)-catalyzed cyclopropanations with trimethylsilylethyl and trichloroethyl aryldiazoacetates
Negretti, Solymar,Cohen, Carolyn M.,Chang, Jane J.,Guptill, David M.,Davies, Huw M.L.
supporting information, p. 7415 - 7420 (2015/08/24)
Abstract Highly functionalized cyclopropanecarboxylates were readily prepared by rhodium-catalyzed cyclopropanation of alkenes with aryldiazoacetates and styryldiazoaceates, in which the ester functionality is either trimethylsilylethyl (TMSE) or trichlor
