108454-55-3Relevant academic research and scientific papers
A Gold- and Br?nsted Acid Catalytic Interplay Towards the Synthesis of Highly Substituted Tetrahydrocarbazoles
Garayalde, David,Rusconi, Giulia,Nevado, Cristina
, (2017)
The reaction of indoles and stabilized cyclopropyl alkynes under gold- and/or gold & Br?nsted acid-catalysis provided access to highly substituted tetrahydrocarbazoles. A mechanistic study revealed the complex mechanism underlying these processes and the opportunistic cooperation of Lewis and Br?nsted acid-catalysts towards the formation of complex molecular scaffolds.
Highly E-selective solvent-free Horner-Wadsworth-Emmons reaction catalyzed by DBU
Ando, Kaori,Yamada, Kyohei
, p. 1143 - 1146 (2011)
The solvent-free Horner-Wadsworth-Emmons reaction of triethyl phosphonoacetate with a variety of aldehydes was catalyzed by DBU in the presence of K2CO3 to give E-α,β-unsaturated esters highly selectively (99:1 for most of the reactions). The reaction with ketones gave trisubstituted olefins with good to high E-selectivity by DBU-Cs2CO3.
Heteroleptic Copper-Based Complexes for Energy-Transfer Processes: E → Z Isomerization and Tandem Photocatalytic Sequences
Cruché, Corentin,Neiderer, William,Collins, Shawn K.
, p. 8829 - 8836 (2021/07/28)
Energy-transfer processes involving copper complexes are rare. Using an optimized heteroleptic copper complex, Cu(bphen)(XantPhos)BF4, photosensitized E → Z isomerization of olefins is demonstrated. The XantPhos ligand afforded sensitizers with improved catalyst stability, while the bphen ligand lengthened the excited-state lifetime. A series of 25 di- and trisubstituted alkenes underwent photoisomerization, including macrocycles and 1,3-enynes. Cu(bphen)(XantPhos)BF4 could also be employed in a tandem ATRA/photoisomerization process employing arylsulfonyl chlorides, an example of photoisomerization with halide-substituted olefins.
Cobalt-Catalyzed Diastereo- And Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates
Wang, Lei,Wang, Lifan,Li, Mingxia,Chong, Qinglei,Meng, Fanke
supporting information, p. 12755 - 12765 (2021/08/30)
Catalytic generation of ambiphilic π-allyl-metal complexes and their utility in enantioselective transformations constitutes a powerful approach for introduction of allyl groups to a molecule. Herein an unprecedented cobalt-catalyzed highly site-, diastereo-, and enantioselective protocol for stereoselective formation of nucleophilic allyl-Co(II) complexes followed by addition to aldehydes is presented. The reaction features diastereo- and enantioconvergent conversion of easily accessible allylic alcohol derivatives to diversified enantioenriched homoallylic alcohols with a remarkably broad scope of allyl groups that can be introduced. Mechanistic studies indicated that allyl radical intermediates were involved in this process. These new discoveries establish a new strategy for development of enantioselective transformations through capture of radicals by chiral Co complexes, pushing forward the frontier of Co complexes for enantioselective catalysis.
Cobalt-Catalyzed Asymmetric 1,4-Hydroboration of Enones with HBpin
Ren, Xiang,Lu, Zhan
supporting information, p. 8370 - 8374 (2021/11/01)
Herein, a series of new 8-OIQ cobalt complexes were synthesized and used for cobalt-catalyzed chemo- and enantioselective 1,4-hydroboration of enones with HBpin to access chiral β,β-disubstituted ketones with good to excellent chemo- and enantioselectivties. This protocol is operationally simple and shows a broad substrate scope.
Copper-catalyzed enantioselective conjugate reduction of α,β-unsaturated esters with chiral phenol–carbene ligands
Mimura, Shohei,Mizushima, Sho,Sawamura, Masaya,Shimizu, Yohei
, p. 537 - 543 (2020/05/14)
A chiral phenol–NHC ligand enabled the copper-catalyzed enantioselective conjugate reduction of α,β-unsaturated esters. The phenol moiety of the chiral NHC ligand played a critical role in producing the enantiomerically enriched products. The catalyst worked well for various (Z)-isomer substrates. Opposite enantiomers were obtained from (Z)- and (E)-isomers, with a higher enantiomeric excess from the (Z)-isomer.
Copper-Photocatalyzed Contra-Thermodynamic Isomerization of Polarized Alkenes
Bouillon, Jean-Philippe,Brégent, Thibaud,Poisson, Thomas
supporting information, p. 7688 - 7693 (2020/10/09)
The contra-thermodynamic isomerization of α- and β-substituted cinnamate derivatives catalyzed by the Cu(OAc)2/rac-BINAP complex under blue light irradiation is reported. The use of an oxazolidinone template, which favored the complexation of the copper catalyst to the substrate, allowed the E → Z isomerization of the catalytically formed chromophore under simple and robust reaction conditions in good to excellent ratios. The mechanism of this process based on the transient formation of a chromophore was also studied.
Visible-Light-Promoted Intramolecular α-Allylation of Aldehydes in the Absence of Sacrificial Hydrogen Acceptors
Liu, Feng,Liu, Jia-Li,tu, Jia-Lin
supporting information, p. 7369 - 7372 (2020/10/05)
We report herein an unprecedented protocol for radical cyclization of aldehydes with pendant alkenes via synergistic photoredox, cobaloxime, and amine catalysis. The transformation was achieved in the absence of external oxidants, providing a variety of 5-, 6-, and 7-membered ring products with alkene transposition in satisfactory yields. The reaction exhibits wide functional group compatibility and occurs under mild conditions with extrusion of H2.
Carbene-Catalyzed Formal [3+3] Cycloaddition Reaction for Access to Substituted 2-Phenylbenzothiazoles
Ni, Zhibin,Mou, Chengli,Zhu, Xun,Qi, Puying,Yang, Song,Chi, Yonggui Robin,Jin, Zhichao
supporting information, p. 492 - 495 (2020/01/24)
A carbene-catalyzed oxidative cycloaddition reaction is developed for efficient access to multi-functionalized 2-phenylbenzothiazoles. A broad scope of heavily substituted arenes bearing 2-benzothiazole groups have been prepared in good to excellent yields. The remote C(sp2)–H bond in the substituted arene products can be activated by Pd catalysts in regio-selective fashion with the direction of the 2-benzothiazole groups.
Catalytic Asymmetric Transfer Hydrogenation of trans-Chalcone Derivatives Using BINOL-derived Boro-phosphates
Na, Fei,Lopez, Susana S.,Beauseigneur, Alice,Hernandez, Lucas W.,Sun, Zhuoxin,Antilla, Jon C.
supporting information, p. 5953 - 5957 (2020/08/12)
Chiral phosphoric-acid-catalyzed asymmetric reductions of trans-chalcones have been investigated in this work. A BINOL-derived boro-phosphate-catalyzed asymmetric transfer hydrogenation of the carbon-carbon double bond of trans-chalcone derivatives employing borane as a hydride source was realized. This methodology provides a convenient procedure to access chiral dihydrochalone derivatives in high yields and with high enantioselectivities under mild conditions.
