33183-30-1Relevant academic research and scientific papers
Merger of visible light induced oxidation and enantioselective alkylation with a chiral iridium catalyst
Wang, Chuanyong,Zheng, Yu,Huo, Haohua,R?se, Philipp,Zhang, Lilu,Harms, Klaus,Hilt, Gerhard,Meggers, Eric
, p. 7355 - 7359 (2015)
Abstract A single chiral octahedral iridium(III) complex is used for visible light activated asymmetric photoredox catalysis. In the presence of a conventional household lamp and under an atmosphere of air, the oxidative coupling of 2-acyl-1-phenylimidazoles with N,N-diaryl-N-(trimethylsilyl)methylamines provides aminoalkylated products in 61-93 % yields with high enantiomeric excess (90-98 % ee). Notably, the iridium center simultaneously serves three distinct functions: as the exclusive source of chirality, as the catalytically active Lewis acid, and as a central part of the photoredox sensitizer. This conceptionally simple reaction Scheme may provide new avenues for the green synthesis of non-racemic chiral molecules. Doing it all alone: A chiral iridium complex is used for visible light activated asymmetric photoredox catalysis by combining photoinduced oxidation with asymmetric Ci-C bond formation.
Independence from the Sequence of Single-Electron Transfer of Photoredox Process in Redox-Neutral Asymmetric Bond-Forming Reaction
Kizu, Tomohito,Uraguchi, Daisuke,Ooi, Takashi
, p. 6953 - 6958 (2016)
A catalytic cycle initiated by the oxidative quenching of the excited photosensitizer (Ir?(ppy)3) is established for the enantioselective coupling between (N-arylamino)methanes and (N-methanesulfonyl)aldimines catalyzed by Ir-based photosensitizer and a chiral (arylamino)phosphonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate under visible light irradiation. This achievement clearly demonstrates the insensitivity of this redox-neutral asymmetric reaction to the sequence of the key redox events involved in the synergistic catalysis.
Selective 1,2-Aryl-Aminoalkylation of Alkenes Enabled by Metallaphotoredox Catalysis
Chen, Zimin,Hu, Yuanyuan,Li, Weirong,Liao, Zixuan,Xi, Xiaoxiang,Yuan, Weiming,Zheng, Songlin
supporting information, p. 17910 - 17916 (2020/08/21)
A highly chemo- and regioselective intermolecular 1,2-aryl-aminoalkylation of alkenes by photoredox/nickel dual catalysis is described here. This three-component conjunctive cross-coupling is highlighted by its first application of primary alkyl radicals, which were not compatible in previous reports. The readily prepared α-silyl amines could be transferred to α-amino radicals by photo-induced single electron transfer step. The radical addition/cross-coupling cascade reaction proceeds under mild, base-free and redox-neutral conditions with good functional group tolerance, and importantly, provides an efficient and concise method for the synthesis of structurally valuable α-aryl substituted γ-amino acid derivatives motifs.
Enantioselective conjugate additions of α-amino radicals via cooperative photoredox and Lewis acid catalysis
Ruiz Espelt, Laura,McPherson, Iain S.,Wiensch, Eric M.,Yoon, Tehshik P.
supporting information, p. 2452 - 2455 (2015/03/04)
We report the highly enantioselective addition of photogenerated α-amino radicals to Michael acceptors. This method features a dual-catalyst protocol that combines transition metal photoredox catalysis with chiral Lewis acid catalysis. The combination of these two powerful modes of catalysis provides an effective, general strategy to generate and control the reactivity of photogenerated reactive intermediates.
