Article
Biochemistry & Molecular Biology
Xiao-Yan Dong, Da-Ming Du
Summary: This paper investigated the organocatalytic asymmetric 1,4-Michael addition reaction of azadienes and alpha-thiocyanoindanones, successfully synthesizing a series of chiral thiocyano compounds. By describing a possible reaction mechanism, it broadens the scope of application of azadiene substrates.
Article
Chemistry, Organic
Viera Polackova, Dominika Kristofikova, Boglarka Nemethova, Renata Gorova, Maria Meciarova, Radovan Sebesta
Summary: Bifunctional N-sulfinylureas and thioureas with an appended pyrrolidine unit were synthesized and evaluated as organocatalysts in Michael additions. The N-sulfinyl-urea catalyst was more efficient than the corresponding thiourea, achieving up to 98% ee enantioselectivities for some substrates. The mode of action was elucidated through DFT calculations, confirming a dual activation mode involving enamine activation of aldehydes and hydrogen-bond activation of nitroalkenes.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Martyna Malinowska, Anna Zawisza
Summary: Bifunctional thioureas and bifunctional thiosquaramides were used as organocatalysts for the first time in the asymmetric Betti reaction, resulting in high yields and enantioselectivity for the synthesis of chiral aminoarylnaphthols and enantioenriched 3-amino-2-oxindoles.
Article
Chemistry, Multidisciplinary
Marta Solas, Samuel Suarez-Pantiga, Roberto Sanz
Summary: This study describes the asymmetric synthesis of cyclopentachromenones from gold-catalyzed reaction of readily available skipped alkenynones. The cascade reaction involves an initial anti-Michael hydroarylation and a subsequent Nazarov cyclization. Excellent enantiomeric ratios and chemical yields are achieved under mild reaction conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Zubeda Begum, Haruka Sannabe, Chigusa Seki, Yuko Okuyama, Eunsang Kwon, Koji Uwai, Michio Tokiwa, Suguru Tokiwa, Mitsuhiro Takeshita, Hiroto Nakano
Summary: Simple primary beta-amino alcohols act as efficient organocatalysts in the asymmetric Michael addition of beta-keto esters with nitroalkenes, producing highly pure chiral Michael adducts. The choice of catalyst and reaction temperature determines the enantiomeric outcome of the adducts.
Article
Chemistry, Organic
Jixin Pian, Qingqing Chen, Yujiao Luo, Zhifei Zhao, Jichang Liu, Lin He, Shi-Wu Li
Summary: An enantioselective cyclopropanation reaction of sulfoxonium ylides with beta,gamma-unsaturated ketoesters catalyzed by a chiral rhodium catalyst has been achieved, leading to the synthesis of various optically pure cyclopropanes.
Article
Chemistry, Multidisciplinary
Jiang-Song Zhai, Dong-Hua Xie, Da-Ming Du
Summary: A new synthetic method has been developed for the synthesis of chiral bispirocyclic indanone compounds through squaramide-catalyzed asymmetric Michael/cyclization tandem reaction. The obtained products were further transformed through oxidation and methylation reactions.
Article
Chemistry, Organic
Daeil Bae, Jin Won Lee, Do Hyun Ryu
Summary: New bifunctional secondary amine organocatalysts derived from L-proline were synthesized and applied in enantioselective Michael reactions in water, yielding high product yields and stereoselectivity. Investigations on the effect of phenyl group at (R)-C6 in the catalyst were conducted, and the successful formal synthesis of a novel histamine H3 receptor agonist, Sch 50971, demonstrated the synthetic utility of this reaction.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Victor Cascales, Hector Carneros, Alejandro Castro-Alvarez, Anna M. Costa, Jaume Vilarrasa
Summary: Chiral nitroalkenes were utilized for the Michael additions of aldehydes for the first time, catalyzed by pyrrolidine derivatives. The asymmetric induction with (S)-proline or (R)-proline was observed, but was limited by the steric hindrance of the catalysts. Nitrocyclobutane intermediates were frequently formed, which were more stable compared to those from (E)-1-nitro-2-phenylethene. The cyclobutanes and final products were characterized using 2D NMR and chemical correlations.
Article
Chemistry, Physical
Hao Xu, Yun-Xuan Tan, Pei-Pei Xie, Rui Ding, Qi Liao, Jian-Wei Zhang, Qing-Hua Li, Yu-Hui Wang, Xin Hong, Guo-Qiang Lin, Ping Tian
Summary: A rhodium(III)-catalyzed asymmetric reductive cyclization was reported for alpha,beta-unsaturated compounds tethered with cyclohexadienone, leading to cis-bicyclic frameworks with good yields and enantioselectivities. The role of ring strain in controlling regioselectivity and favoring 5,6-bicyclic products was also demonstrated by DFT calculations.
Article
Chemistry, Organic
Ye Zhang, Jingcheng Guo, Jinna Han, Xiangui Zhou, Wei Cao, Zhenqian Fu
Summary: The bifunctional squaramide-catalyzed nucleophilic addition of thiophenols to easily available beta-silyl alpha,beta-unsaturated carbonyl compounds has been successfully developed, leading to the efficient preparation of a structurally diverse set of chiral alpha-mercaptosilanes with good to excellent yields and acceptable enantioselectivities. The reaction features mild reaction conditions, a broad substrate scope, and easy scale-up.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Jiang-Song Zhai, Da-Ming Du
Summary: A bifunctional thiourea-catalyzed asymmetric [3 + 2] annulation reaction has been developed to synthesize chiral dispiro[indene-pyrrolidine-pyrimidine] compounds from 2-isothiocyanato-1-indanones and barbiturate-based olefins. The reaction has shown excellent yields and stereoselectivities. The synthetic utility of the products has been demonstrated through gram-scale synthesis, one-pot three-component reactions, and further transformation experiments.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Li-Xia Liu, Yu-Qing Bai, Xiang Li, Chang-Bin Yu, Yong-Gui Zhou
Summary: Combining base-promoted retro-sulfa-Michael addition with palladium-catalyzed asymmetric allenylic alkylation, a streamlined synthesis of chiral thiochromanones containing two central chiralities (including a quaternary stereogenic center) and an axial chirality (allene unit) was successfully achieved, with yields up to 98%, dr of 49.0:1, and >99% ee.
Article
Chemistry, Organic
Xinpeng Cheng, Liming Zhang
Summary: This work describes an asymmetric gold-ligand cooperative catalysis for the transformation of readily accessible chiral/achiral propargylic sulfonamides into chiral 3-pyrrolines. A bifunctional biphenyl-2-ylphosphine ligand containing a chiral tetrahy-droisoquinoline fragment is crucial for the observed metal-ligand cooperation and asymmetric induction. The reaction can provide 2,5-cis-3-pyrrolines with excellent diastereoselectivities in a matched scenario, and 2,5-trans-3-pyrrolines with >5/1 diastereoselectivity in a mismatched scenario using the ligand enantiomer. The synthetic utilities of this chemistry have been demonstrated.
Article
Chemistry, Organic
Chun-Tai Hung, Chun-Wei Lu, Shi-Han Huang, Yin-Feng Lu, Hsiang-Chi Chou, Cheng-Che Tsai
Summary: This research utilizes chiral sulfinamides as nucleophiles in intramolecular allylic substitution and sequential aerobic oxidation with aza-Michael addition reactions, achieving good yields of chiral isoindolines and high diastereoselectivities.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Faiza Diaba, Gisela Trenchs
Summary: The first violet light-mediated synthesis of gamma- and delta-lactams from N-alkenyl trichloroacetamides is reported in this paper. The reactions are conducted in tetrahydrofuran or 2-methyltetrahydrofuran as the sole solvent without catalysts or additives, under non-anhydrous conditions in an air atmosphere where the solvent serves as the radical initiator.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Feroze Hussain, Sajjad Ahmed, Ashiq Hussain Padder, Qazi Naveed Ahmed
Summary: This study reports a novel and efficient one-pot synthesis method for mixed phosphorotrithioates, which does not require supplementary additives and shows broad applicability.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Hyunjin Oh, Ikyon Kim
Summary: A new 1,2,4-triazole-pyrrolo[1,2-a]pyrazine hybrid system, 6-acylpyrrolo[1,2-a][1,2,4]triazolo[5,1-c]pyrazine, was synthesized using a catalyst-free method. This method involved sequential exposure of pyrrole-2-carbonitrile-derived substrates to DMF-DMA and acyl hydrazide, resulting in the formation of acylated pyrazine and 1,2,4-triazole rings, enabling the installation of various substituents at specific positions on the core skeleton.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Ming Yan, Si-fan Wang, Yong-po Zhang, Jin-zhong Zhao, Zhuo Tang, Guang-xun Li
Summary: Here we developed an efficient photocatalytic approach for the convenient preparation of sulfinamides. The reaction allows for the gram-scale preparation of sulfinamides and the one-pot synthesis of various sulfonyl amides.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Farzaneh Bandehali-Naeini, Zahra Tanbakouchian, Noushin Farajinia-Lehi, Nicolas Mayer, Morteza Shiri, Martin Breugst
Summary: Two tandem catalytic systems were developed for the synthesis of novel 3,4-disubstituted maleimides using the same Ugi adducts. Different maleimide structures can be synthesized using either Pd or Cu catalysis.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Article
Chemistry, Organic
Tanya Raghava, Anjan Chattopadhyay, Subhadeep Banerjee, Nivedita Sarkar
Summary: Amine substitution of two ortho fluorine atoms of tetrafluoroterephthalonitrile through SNAr chemistry is easily achievable. But further fluorine substitution is only possible under forcing conditions, yielding valuable fluorophores for bioimaging.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)
Review
Chemistry, Organic
Anju Chadha, Santosh Kumar Padhi, Selvaraj Stella, Sowmyalakshmi Venkataraman, Thangavelu Saravanan
Summary: Alcohol dehydrogenases are enzymes that use cofactors for oxidation or reduction reactions of alcohols or carbonyl compounds. They are utilized in green chemistry and have applications in the production of pharmaceuticals. Recombinant enzymes have solved the challenge of producing purified enzymes in large quantities. Engineered alcohol dehydrogenases have been used in asymmetric synthesis in industry. Various methods have been established for regenerating expensive cofactors to make the enzymatic process more efficient and economically viable.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2024)