Qingyun Wang, Shuquan Wu, Juan Zou, Xuyang Liang, Chengli Mou, Pengcheng Zheng, and Yonggui Robin Chi
Nature Communications, Vol 14, Iss 1, Pp 1-10 (2023)
Subjects
Science
Abstract
Abstract A carbene-catalyzed asymmetric access to chiral β-cyano carboxylic esters is disclosed. The reaction proceeds between β,β-disubstituted enals and aromatic thiols involving enantioselective protonation of enal β-carbon. Two main factors contribute to the success of this reaction. One involves in situ ultrafast addition of the aromatic thiol substrates to the carbon-carbon double bond of the enal substrate. This reaction converts almost all enal substrate to a Thiol-click Intermediate, significantly reducing aromatic thiol substrates concentration and suppressing the homo-coupling reaction of enals. Another factor is an in situ release of enal substrate from the Thiol-click Intermediate for the desired reaction to proceed effectively. The optically enriched β-cyano carboxylic esters from our method can be readily transformed to medicines that include γ-aminobutyric acids derivatives such as Rolipram. In addition to synthetic utilities, our control of reaction outcomes via in situ substrate modulation and release can likely inspire future reaction development.
Shi-Chao Ren, Xing Yang, Bivas Mondal, Chengli Mou, Weiyi Tian, Zhichao Jin, and Yonggui Robin Chi
Nature Communications, Vol 13, Iss 1, Pp 1-10 (2022)
Subjects
Science
Abstract
The combination of carbene- and photocatalysis has enabled unorthodox routes to ketone syntheses, but usually requires engineered or activated substrates. Herein the authors present a carbene- and photocatalytic decarboxylative radical coupling of carboxylic acids and acyl imidazoles, in which the carboxylic acids are directly used as radical precursors.
Yingguo Liu, Qiao Chen, Chengli Mou, Lutai Pan, Xiaoyong Duan, Xingkuan Chen, Hongzhong Chen, Yanli Zhao, Yunpeng Lu, Zhichao Jin, and Yonggui Robin Chi
Nature Communications, Vol 10, Iss 1, Pp 1-8 (2019)
Subjects
Science
Abstract
Phthalidyl esters, commonly used prodrug moieties, are mostly prepared as a racemate. Here, the authors report an N-heterocylcic carbene-catalysed enantioselective acetalization of carboxylic acids and dialdehydes to give phthalidyl esters in high yields with good enantioselectivity.
A chemo- and diastereo-selective (3 + 2) cycloaddition reacition between Donor-Acceptor (D-A) cyclopropanes and α,β-unsaturated enamides is developed for efficient access to spiro(cyclopentane-1,3'-indoline) derivatives. Simple, inexpensive and readily available NaOH is used as the sole catalyst for this process. A broad range of D-A cyclopropanes could be used as the C-3 synthons to react with oxindole-derived α,β-unsaturated enamides. The structurally sophisticated spiro(cyclopentane-1,3'-indoline) derivatives bearing up to 3 adjacent chiral centers are afforded in excellent yields as single diastereomers.
Yonggui Robin Chi, Song Yang, Zhijian Huang, Chengli Mou, Baoan Song, Baosheng Li, and Xuan Huang
ChemInform. 47
Subjects
General Medicine, Chemistry, Stereocenter, Organic chemistry, Desymmetrization, Bisphenol, Catalysis, Organocatalysis, Carbene, and chemistry.chemical_compound
Abstract
A carbene-catalyzed desymmetrization of prochiral bisphenol compounds bearing remote P-stereogenic centers is disclosed. The catalytic reactions can be performed on gram scales with 1 mol % N-heterocyclic carbene (NHC) catalyst, providing efficient access to enantiomerically enriched P-stereogenic phosphinates. The chiral phosphinates prepared with our method can find widespread applications as asymmetric organic catalysts and ligands.
Tingshun Zhu, Pengcheng Zheng, Yonggui Robin Chi, Song Yang, Baoan Song, and Chengli Mou
ChemInform. 47
Subjects
General Medicine, Aryl, chemistry.chemical_compound, chemistry, Ring (chemistry), Combinatorial chemistry, Molecule, Total synthesis, Reagent, Natural product, Lactone, chemistry.chemical_classification, and Intramolecular force
Abstract
Benzocoumarin is an important structural motif widely found in natural products and synthetic molecules. Traditional methods for the synthesis of benzocoumarins and their derivatives require multiple steps, typically with an intramolecular ester forming reaction to make the lactone ring as the last step. Another major method involves transition metal-catalyzed coupling or carbon-hydrogen bond activation reactions starting with pre-existing aryl frameworks in the substrates. Here we report a new strategy for the green and rapid access to benzocoumarins and their derivatives. Our method uses readily available unsaturated aldehydes and coumarins as the substrates and air as the green oxidant. The overall reaction proceeds through a formal [4+2] process to construct a new benzene ring and thus to afford benzocoumarins in essentially a single step. No metal catalysts were used; no toxic or expensive reagents were involved. The power of our new approach is further demonstrated in a concise formal total synthesis of cannabinol, a bioactive natural product.
Background: Plant fungi (e.g., Pellicularia sasakii, Gibberella zeae, Fusarium oxysporum, and Cytospora mandshurica and Phytophthora infestans) and bacteria (e.g., Ralstonia solanacearum) are extremely difficult to manage in agricultural production. The high incidence of plant mortality and the lack of effective control methods make P. sasakii and R. solanacearum two of the world's most destructive plant pathogens. Pathogenic fungi and bacteria are responsible for billions of dollars in economic losses worldwide each year. Thus, we designed an active amide structure and synthesized a series of novel amide derivatives containing a triazole moiety to discover new bioactive molecules and pesticides that can act against fungi and bacteria. Results: A series of amide derivatives containing a triazole moiety were synthesized. All the obtained compounds were characterized through proton and carbon nuclear magnetic resonance spectroscopy, infrared spectroscopy, and elemental analysis. Preliminary antifungal activity test showed that some of the synthesized compounds exhibited moderate antifungal activity against P. sasakii, G. azeae, F. oxysporum, C. mandshurica, and P. infestans at 50 mg/L. Compound 4u displayed more potent antifungal activity against P. sasakii and G. azeae than hymexazol. Preliminary antibacterial activity results showed that some of the synthesized compounds exhibited high antibacterial activity against R. solanacearum at 200 mg/L. Compounds 4m and 4q displayed high antibacterial activity against R. solanacearum, with 71% and 65% inhibitory rates, respectively. Conclusions: A series of novel amide derivatives containing 1,2,4-triazole moiety were synthesized through the reaction of intermediate 3 with different acyl chlorides and anhydrous potassium carbonates in anhydrous tetrahydrofuran at 50°C, using 2,4-dichloroacetophenoneas as a starting material. The title compounds exhibited high inhibitory effects against P. sasakii, R. solanacearum, and G. azeae. [ABSTRACT FROM AUTHOR]
