Article
Chemistry, Multidisciplinary
Jolene P. Reid, Isaiah O. Betinol, Yutao Kuang
Summary: The application of mechanistic generalizations is essential for the development and application of chemical reactions. These strategies are based on physical organic chemistry and allow for the understanding of one reaction to be applied to explaining another. Over time, these techniques have evolved from rationalizing observed outcomes to guiding experimental design through reaction prediction. In this feature article, the authors describe the models used to generalize organocatalytic reaction mechanisms and demonstrate their effectiveness in accelerating enantioselective synthesis.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Ming Chen, Guangbin Dong
Summary: This article describes a platinum-catalyzed desaturation of cyclic ketones to their conjugated alpha,beta-unsaturated counterparts, which operates under mild conditions without the need for strong bases or acids. The method shows good functional group tolerance and can be applied to diverse and complex structures. The mechanism involves fast and reversible alpha-deprotonation followed by a rate-determining beta-hydrogen elimination process, distinguishing it from prior palladium-catalyzed methods.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Francesco Calogero, Simone Potenti, Elena Bassan, Andrea Fermi, Andrea Gualandi, Jacopo Monaldi, Busra Dereli, Bholanath Maity, Luigi Cavallo, Paola Ceroni, Pier Giorgio Cozzi
Summary: In this study, a highly enantioselective photoredox allylation of aldehydes was developed using commercially available allyl acetate and chiral nickel complexes as the catalyst. The reaction proceeded under visible-light irradiation at low temperature, providing good to excellent yields and high enantioselectivity. This methodology shows great potential for practical applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Akira Saito, Shinya Adachi, Naoya Kumagai, Masakatsu Shibasaki
Summary: The strategic use of a sterically demanding Ni-II pincer carbene complex has enabled high enantioselectivity in the direct catalytic asymmetric addition of acetonitrile to aldehydes, resulting in highly enantioenriched beta-hydroxynitriles. This highly atom-economical process offers a promising pathway for utilizing inexpensive acetonitrile as a C2 building block in practical synthetic toolbox for asymmetric catalysis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Luigi Dolcini, Tommaso Gandini, Riccardo Castiglioni, Alberto Bossi, Marta Penconi, Alberto Dal Corso, Cesare Gennari, Luca Pignataro
Summary: This study investigates the use of organic photocatalysts for visible light-promoted beta-functionalization of carbonyl compounds. Donor-acceptor cyanoarenes showed the best results among the tested dyes, promoting the desired transformations in moderate to good yields. The reaction scope was explored on substrates with different steric and electronic properties, and a reductive quenching mechanism involving a transient 5 pi e(-) activation mode was proposed based on fluorescence quenching analysis.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Marina Briand, Linh D. Thai, Flavien Bourdreux, Nicolas Vanthuyne, Xavier Moreau, Emmanuel Magnier, Elsa Anselmi, Guillaume Dagousset
Summary: Site-selective trifluoromethylation of silyl dienol ethers derived from alpha,ss-unsaturated aldehydes, ketones, and amides was achieved for the first time in the remote gamma position. An unprecedented enantioselective C(sp(3))-H perfluoroalkylation process is disclosed.
Article
Chemistry, Multidisciplinary
J. Daniel Bailey, Edward Helbling, Amey Mankar, Matthew Stirling, Fred Hicks, David K. Leahy
Summary: Reducing or eliminating organic solvent use in pharmaceutical manufacturing is a highly effective way to reduce environmental, health, and safety impacts. The process described utilizing primarily water-based methods significantly reduces material inputs and organic solvent use, while surprisingly using less water and improving overall yield compared to traditional methods.
Article
Chemistry, Organic
Xiaohan Li, Karthik S. Iyer, Ruchita R. Thakore, David K. Leahy, J. Daniel Bailey, Bruce H. Lipshutz
Summary: Highly valued products can be produced through reductive aminations using shelf-stable bisulfite addition compounds of aldehydes under aqueous micellar catalysis conditions. The readily available alpha-picolineborane serves as the stoichiometric hydride source, and recycling of the aqueous reaction medium is easily achieved. Several applications to targets in the pharmaceutical industry have been documented.
Article
Chemistry, Organic
Makoto Ono, Yuji Sumii, Yamato Fujihira, Takumi Kagawa, Hideyuki Mimura, Norio Shibata
Summary: The micro-flow nucleophilic pentafluoroethylation using pentafluoroethane (HFC-125) as a reagent is described, achieving good to high yields of pentafluoroethyl carbinols from a variety of ketones, aldehydes, and chalcones with substituted benzene rings at room temperature or -10 degrees C in DMF or toluene with a potassium base.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Shuai Huang, Fei-Fei Tong, Da-Chang Bai, Gao-Peng Zhang, Yang-Jie Jiang, Bo Zhang, Xuebing Leng, Ying-Long Guo, Xiao-Long Wan, Xingang Zhang, Chang-Hua Ding, Xue-Long Hou
Summary: This study presents a method for difluoroallylation of hydrazones via palladium and N-heterocyclic carbene catalysis, yielding products with high yields and selectivities. The use of chiral N-heterocyclic carbene as a ligand is crucial for enhancing selectivities and reaction productivity.
NATURE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Mouxin Huang, Long Zhang, Tianrun Pan, Sanzhong Luo
Summary: This study presents a distinctive photochemical E/Z isomerization strategy for the deracemization of α-branched aldehydes, which involves the use of simple aminocatalysts and readily available photosensitizers. The method enables the direct transformation of racemic α-branched aldehydes into enantiopure α-tertiary carbonyls with high selectivity.
Article
Chemistry, Organic
Xian-Tao Wu, Feng Ma, En-Kai Xiao, Jin Yin, Fuxing Sun, Qiang Wang, Yi-Jun Jiang, Peng Chen
Summary: A simple and efficient methodology for the first synthesis of tri- and di-fluoromethyl-bis(indolyl)methanols has been demonstrated through a one-pot Friedel-Crafts-type acylation-alkylation of readily available indoles and fluorinated acids. This method was performed under metal-, additive-, toxic-solvent-, and protective-gas-free conditions, delivering a wide range of products in moderate to high yields. The reaction can tolerate diverse functional groups and can be readily scaled up without significant decrease in yield, showing its high application potential.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Physical
Nora Almutairi, Srikanth Vijjamarri, Guodong Du
Summary: Manganese (III) complexes supported by salan ligands were synthesized and examined as catalysts in the hydrosilylation of carbonyl compounds. Manganese (III) chloride complexes exhibited minimal catalytic efficacy without activation of silver perchlorate, while manganese (III) azide complexes showed good activity in this reaction. Under optimized conditions, various aldehydes and ketones could be reduced with high yields and tolerance to different functional groups. The possible mechanisms of silane activation and hydrosilylation were discussed based on experimental observations.
Article
Chemistry, Organic
Yaseen Hussain, Deepak Sharma, Pankaj Chauhan
Summary: An unprecedented highly stereoselective synthesis of pyrrolo[1,2-d][1,4]oxazepin-3(2H)-ones has been achieved through photoredox/N-heterocyclic carbene (NHC) relay catalysis. Substituted dibenzoxazepines and aryl/heteroaryl enals were successfully converted to dibenzoxazepine-fused pyrrolidinones with excellent diastereo- and enantioselectivities via amine oxidation and [3 + 2] annulation reactions catalyzed by organic photoredox catalysis and NHC, respectively.
Article
Chemistry, Organic
Yaseen Hussain, Deepak Sharma, Tamanna, Pankaj Chauhan
Summary: A novel and highly selective synthesis of pyrrolo[1,2-d][1,4]oxazepin-3(2H)-ones has been achieved using photoredox/N-heterocyclic carbene (NHC) relay catalysis. Various substituted dibenzoxazepines and aryl/hetereoaryl enals were efficiently converted to imines through the organic photoredox catalysis-promoted amine oxidation, followed by a NHC-catalyzed [3 + 2] annulation reaction to afford dibenzoxazepine-fused pyrrolidinones with excellent diastereo- and enantioselectivities.
