Review
Chemistry, Multidisciplinary
Cheng Niu, Da-Ming Du
Summary: This review highlights the recent advancements in sulfa-Michael addition-triggered cascade reactions for the stereoselective synthesis of sulfur-containing compounds. It discusses various types of reactions, including sulfa-Michael/aldol, sulfa-Michael/Henry, sulfa-Michael/Michael, sulfa-Michael/Mannich and some sulfa-Michael triggered multi-step processes. The review also introduces reaction mechanisms and derivatization experiments.
Article
Chemistry, Multidisciplinary
Tibor Penaska, Viktoria Modrocka, Klara Stankovianska, Maria Meciarova, Erik Rakovsky, Radovan Sebesta
Summary: This study achieves enantioselective and diastereoselective synthesis of densely substituted chiral pyran derivatives by using amino-thiourea or quinine organocatalyst under ball-milling conditions. Liquid-assisted grinding proves to be a highly efficient means of obtaining pyrans in high yield, with high enantiomeric purities and short reaction times.
Article
Chemistry, Organic
Deniz Tozendemir, Cihangir Tanyeli
Summary: Cinchona alkaloid-derived organocatalysts have been widely utilized in asymmetric transformations, resulting in products with high enantiopurity. A bifunctional quinine-derived sulfonamide organocatalyst was developed for catalyzing the asymmetric sulfa-Michael reaction, achieving high enantioselectivity with low catalyst loading. The enriched sulfa-Michael addition products were successfully oxidized to obtain the corresponding sulfones.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Hanbin Lu, Jiamin Lv, Canhua Zhou, Mi Zhou, Yanxiong Fang, Jinxiang Dong, Terumasa Kato, Yan Liu, Keiji Maruoka
Summary: In this study, a catalytic asymmetric direct Michael reaction of ketones with trans-beta-arylnitroethenes was successfully achieved under the influence of optically pure L-hydroxyproline-based secondary-amino aromatic Tf-amide organocatalyst. The addition of trialkylamine base additives, such as diethylmethylamine, played a crucial role in achieving high reactivity and enantioselectivity in this asymmetric Michael reaction.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Applied
Jen-Yu Kuan, I-Ting Chen, Hsuan Lin, Jeng-Liang Han
Summary: We have developed a substrate-dependent, regio- and stereocontrolled diversity-oriented organocatalytic vinylogous Michael addition/cyclization cascade of 2-alkylidene indane-1,3-diones with enals, using secondary amines as the catalyst. This method allows for the selective synthesis of spiroindane-1,3-diones, tetrahydrofluoren-9-one derivatives, and benzofused oxabicyclo[3.3.1]nonanes. Plausible catalytic pathways have been proposed, and DFT calculations have clarified the mechanisms involved.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Patricia B. Momo, Eduardo F. Mizobuchi, Radell Echemendia, Isabel Baddeley, Matthew N. Grayson, Antonio C. B. Burtoloso
Summary: Enantioselective sulfa-Michael additions to alpha,beta-unsaturated diazocarbonyl compounds have been developed using quinine-derived squaramide as the catalyst. This method allows the formation of C-S bonds with high stereoselectivity for alkyl and aryl thiols. The synthesis of 22 examples showed enantiomeric ratios up to 97:3 and reaction yields up to 94%. Density functional theory (DFT) calculations were used to determine the mechanism and origins of enantioselectivity.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Applied
Claire Segovia, Jeremy Godemert, Jean-Francois Briere, Vincent Levacher, Sylvain Oudeyer
Summary: An organocatalyzed one-pot sequential deracemization of aromatic ketones with a stereogenic center at the alpha-position was achieved through an acid-base strategy, in which enantioselective protonation reaction played a key role. This protocol provides enantioenriched ketones with up to 89% ee without isolating sensitive intermediates like silyl enolates. Water was found to be crucial in this process. This one-pot sequence serves as a valuable extension to previously reported chemically driven red-ox protocols, expanding the range of molecules eligible for deracemization.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Maria Sanchez-Rosello, Marcos Escolano, Daniel Gavina, Carlos del Pozo
Summary: The asymmetric intramolecular aza-Michael reaction (IMAMR) is a convenient strategy for generating heterocycles with nitrogen-substituted stereocenters, finding widespread applications in the total synthesis of alkaloids and biologically relevant compounds. Recent developments in asymmetric versions of IMAMR mainly involve the use of organocatalysts, such as chiral imidazolidinones and diaryl prolinol derivatives. The use of N-sulfinyl imines with dual roles has also emerged as a versatile mode for performing the asymmetric IMAMR.
Article
Chemistry, Multidisciplinary
Xiu-Ning Hu, Dong-Ping Wu, Ye-Peng Xu, Pei-Qiang Huang
Summary: The first organocatalytic asymmetric synthesis of an advanced intermediate of (+)-sarain A was achieved by combining organocatalytic asymmetric Michael addition reaction and a nitrogen-to-carbon chirality transfer. This method allows for the construction of three chiral centers and chemoselective reduction of a key lactam intermediate, providing a tricyclic intermediate with all necessary functionalities for further elaboration into (+)-sarain A.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Hiromasa Ogawa, Hiroto Okawa, Keiji Mori
Summary: We investigated the effects of substituents on the aromatic rings in a diarylmethylamine unit, which we named the 'butterfly'-type amine unit, in an aminothiourea catalyst. The catalyst with a 3,5-bis(trifluoromethyl)phenyl group showed the best results, achieving excellent chemical yield and enantioselectivity in an asymmetric Michael reaction. Importantly, this catalyst demonstrated superior catalytic ability as a chiral catalyst compared to the well-known Takemoto catalyst, and this characteristic was observed in various asymmetric reactions.
Article
Chemistry, Multidisciplinary
Muhammad Sohail, Fujie Tanaka
Summary: The DYKAT reactions can transform dihydrobenzofuranone derivatives into spirooxindole derivatives with high enantioselectivities and yields, regardless of the stereochemistry of the starting materials.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Multidisciplinary
Corinne Coutant, Paul De Bonfils, Pierrick Nun, Vincent Coeffard
Summary: The advent of asymmetric organocatalysis has revolutionized the way chemists create or break chemical bonds, enabling new strategies for enantioselective functionalization. This success is attributed to various activation modes and the availability of numerous chiral organic catalysts. Selective functionalization of compounds with multiple activation sites, such as cyclohexanone-derived dienones, has also contributed to breakthroughs in this field. These compounds can undergo diverse transformations and offer new opportunities for natural product synthesis. This review focuses on intermolecular functionalization of (cross)-conjugated cyclohexanone-derived compounds using asymmetric organocatalysis.
Article
Chemistry, Applied
Irma Garcia-Monzon, Jorge Borges-Gonzalez, Tomas Martin
Summary: The heterogenization of homogeneous catalysts onto a solid support is a crucial step towards sustainable chemistry. In this study, we developed a series of polymer-supported tetrahydropyran-based hybrid dipeptides as active catalysts for the enantioselective Michael addition of aldehydes to beta-nitrostyrenes. The optimal anchor position and orientation between the catalyst and solid support, as well as the linker length, were carefully designed to enhance the catalytic efficiency. These supported catalysts exhibited high yields and enantiomeric excesses, and detailed deactivation studies provided important insights for prolonging their useful life.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Editorial Material
Chemistry, Organic
Nimisha Bania, Dipankar Barman, Subhas Chandra Pan
Summary: An organocatalytic asymmetric oxa-Michael-Michael reaction was developed for the synthesis of spirotetrahydropyranopyrazolones. By utilizing a quinine-derived squaramide catalyst, the reaction achieved moderate yields, excellent diastereomeric ratios, and high to excellent enantioselectivities under mild reaction conditions.
Article
Chemistry, Organic
Prasenjit Gayen, Prasanta Ghorai
Summary: A highly chemoselective 1,2-addition of thiols with 2-isothiocyanatochalcones followed by an enantioselective intramolecular thia-Michael addition cascade has been developed for the synthesis of enantioenriched [1,3]-benzothiazine derivatives. The squaramide catalyst derived from cinchona provides excellent yield and enantioselectivity with a wide range of substrates. Furthermore, this strategy can be extended to access enantioenriched organophosphorus-substituted [1,3]-benzothazines using diphenylphosphine oxide nucleophile.
