345-88-0Relevant academic research and scientific papers
Photoredox-Catalyzed α-Aminomethyl Carboxylation of Styrenes with Sodium Glycinates: Synthesis of γ-Amino Acids and γ-Lactams
Zhou, Cong,Li, Miao,Sun, Jianwei,Cheng, Jiang,Sun, Song
supporting information, p. 2895 - 2899 (2021/05/05)
A visible-light photoredox-catalyzed reductive α-aminomethyl carboxylation of styrenes with sodium glycinates and CO2 has been developed to synthesize a series of α,α-disubstituted γ-amino acids and γ-lactams with high efficiency and regioselectivity. Notably, CO2 released from the decarboxylation step can be reused for the subsequent carboxylation. Distinct from the previous reactions with the same type of substrates leading to simple decarboxylation and olefin hydroalkylation, this process involves additional CO2 sequestration, thus leading to olefin α-aminomethyl carboxylation. These findings not only provide new access to α,α-disubstituted γ-amino acids and γ-lactams but also serve as a proof of concept for CO2 reutilization in decarboxylation reactions.
Photochemical Formal (4 + 2)-Cycloaddition of Imine-Substituted Bicyclo[1.1.1]pentanes and Alkenes
Harmata, Alexander S.,Sowden, Madison J.,Spiller, Taylor E.,Stephenson, Corey R. J.
supporting information, p. 21223 - 21228 (2021/12/27)
Amines containing bridged bicyclic carbon skeletons are desirable building blocks for medicinal chemistry. Herein, we report the conversion of bicyclo[1.1.1]pentan-1-amines to a wide range of polysubstituted bicyclo[3.1.1]heptan-1-amines through a photochemical, formal (4 + 2)-cycloaddition of an intermediate imine diradical. To our knowledge, this is the first reported method to convert the bicyclo[1.1.1]pentane skeleton to the bicyclo[3.1.1]heptane skeleton. Hydrolysis of the imine products gives complex, sp3-rich primary amine building blocks.
Photoinduced Hydroarylation and Cyclization of Alkenes with Luminescent Platinum(II) Complexes
Cheng, Hanchao,Lam, Tsz-Lung,Liu, Yungen,Tang, Zhou,Che, Chi-Ming
supporting information, p. 1383 - 1389 (2020/11/30)
Photoinduced hydroarylation of alkenes is an appealing synthetic strategy for arene functionalization. Herein, we demonstrated that aryl radicals generated from electron-deficient aryl chlorides/bromides could be trapped by an array of terminal/internal aryl alkenes in the presence of [Pt(O^N^C^N)] under visible-light (410 nm) irradiation, affording anti-Markovnikov hydroarylated compounds in up to 95 % yield. Besides, a protocol for [Pt(O^N^C^N)]-catalyzed intramolecular photocyclization of acrylanilides to give structurally diverse 3,4-dihydroquinolinones has been developed.
Direct Allylic C(sp3)?H and Vinylic C(sp2)?H Thiolation with Hydrogen Evolution by Quantum Dots and Visible Light
Huang, Cheng,Ci, Rui-Nan,Qiao, Jia,Wang, Xu-Zhe,Feng, Ke,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
supporting information, p. 11779 - 11783 (2021/04/21)
Direct allylic C?H thiolation is straightforward for allylic C(sp3)?S bond formation. However, strong interactions between thiol and transition metal catalysts lead to deactivation of the catalytic cycle or oxidation of sulfur atom under oxidative condition. Thus, direct allylic C(sp3)?H thiolation has proved difficult. Represented herein is an exceptional for direct, efficient, atom- and step-economic thiolation of allylic C(sp3)?H and thiol S?H under visible light irradiation. Radical trapping experiments and electron paramagnetic resonance (EPR) spectroscopy identified the allylic radical and thiyl radical generated on the surface of photocatalyst quantum dots (QDs). The C?S bond formation does not require external oxidants and radical initiators, and hydrogen (H2) is produced as byproduct. When vinylic C(sp2)?H was used instead of allylic C(sp3)?H bond, the radical-radical cross-coupling of C(sp2)?H and S?H was achieved with liberation of H2. Such a unique transformation opens up a door toward direct C?H and S?H coupling for valuable organosulfur chemistry.
Direct 1,2-Dicarbonylation of Alkenes towards 1,4-Diketones via Photocatalysis
Chen, Bin,Cheng, Yuan-Yuan,Hou, Hong-Yu,Lei, Tao,Tung, Chen-Ho,Wu, Li-Zhu,Yu, Ji-Xin
supporting information, p. 26822 - 26828 (2021/11/17)
1,4-Dicarbonyl compounds are intriguing motifs and versatile precursors in numerous pharmaceutical molecules and bioactive natural compounds. Direct incorporation of two carbonyl groups into a double bond at both ends is straightforward, but also challenging. Represented herein is the first example of 1,2-dicarbonylation of alkenes by photocatalysis. Key to success is that N(n-Bu)4+ not only associates with the alkyl anion to avoid protonation, but also activates the α-keto acid to undergo electrophilic addition. The α-keto acid is employed both for acyl generation and electrophilic addition. By tuning the reductive and electrophilic ability of the acyl precursor, unsymmetric 1,4-dicarbonylation is achieved for the first time. This metal-free, redox-neutral and regioselective 1,2-dicarbonylation of alkenes is executed by a photocatalyst for versatile substrates under extremely mild conditions and shows great potential in biomolecular and drug molecular derivatization.
Deaminative carbonylative coupling of alkylamines with styrenes under transition-metal-free conditions
Zhao, Fengqian,Li, Chong-Liang,Wu, Xiao-Feng
supporting information, p. 9182 - 9185 (2020/08/26)
A transition-metal-free deaminative carbonylation of alkylamines with styrenes has been developed. The reaction shows good functional group compatibility and various α,β-unsaturated ketones were obtained in moderate to good yields. The alkyl radical generated from Katritzky salts via base-promoted C-N bond cleavage is one of the key intermediates in this reaction. This journal is
Bimolecular vinylation of arenes by vinyl cations
Bour, Christophe,Gandon, Vincent,Li, Zhilong
supporting information, p. 6507 - 6510 (2020/07/02)
Styrene derivatives can be easily synthesized from vinyl triflates and arenes under mild reaction conditions, using [Li][Al(OC(CF3)3)4] as a catalyst and LiHMDS as a base. This transformation is likely to involve a vinyl cation intermediate as an electrophile, which is corroborated by DFT calculations, deuterium-labeling and other control experiments. The use of an inert weakly coordinating anion is a decisive factor in this bimolecular vinylation process. This journal is
Bisoxazoline-pincer ligated cobalt-catalyzed hydrogenation of alkenes
Ritz, Mikhaila D.,Parsons, Astrid M.,Palermo, Philip N.,Jones, William D.
supporting information, (2020/02/13)
The efficient and atom economical hydrogenation of alkenes using a novel bisoxazoline ligated cobalt complex has been developed. The hydrogenation of a variety of alkenes containing electron neutral and electron-donating groups proceeds in high yield, whi
Overcoming Scope Limitations in Cross-Coupling of Diazo Nucleophiles by Manipulating Catalyst Speciation and Using Flow Diazo Generation
Sullivan, Ryan J.,Freure, Garrett P.R.,Newman, Stephen G.
, p. 5623 - 5630 (2019/06/05)
The accessible scope of palladium-catalyzed diazo cross-coupling reactions has been expanded to include aryl chlorides by controlled diazo slow addition. The success of this strategy is based on manipulating speciation within the catalytic cycle through starvation of the diazo reagent to make the Pd(II) oxidative intermediate the resting state. The strategy is also applicable to cross-coupling reactions with aryl bromides and, in combination with safe, on-demand flow generation of nonstabilized diazo reagents, has been used to greatly expand the scope of applicable diazo compounds for this chemistry as well. Lastly, DFT calculations have provided insight into the mechanism and support for the proposed explanation for success of the slow addition strategy.
Single-pot access to bisorganoborinates: Applications in zweifel olefination
Music, Arif,Baumann, Andreas N.,Spie?, Philipp,Hilgert, Nicolas,K?llen, Martin,Didier, Dorian
supporting information, p. 2189 - 2193 (2019/04/10)
Zweifel olefination is a catalyst-free reaction that serves alkene functionalization. While most methods employ commercially available boron pinacol esters, we have assembled a sequence in which the two partners of the formal coupling reaction are installed successively, starting from inexpensive boron alkoxides. The in situ formation of bisorganoborinates was accomplished by consecutive reaction of two different organometallic species. This single-pot procedure represents a great advancement in the generation of organoborinates and their involvement in C-C bond formation.
