Article
Chemistry, Multidisciplinary
Changli He, Xiaoxue Tang, Xin He, Yuqiao Zhou, Xiaohua Liu, Xiaoming Feng
Summary: Reversal of regioselectivity in the catalytic asymmetric conjugate additions of 3-substituted oxindoles to beta-nitroenones or beta-nitroacrylates was achieved with chiral scandium catalysts. Functionalized 3,3-disubstituted oxindoles, including terminal and internal vinyl groups, were constructed in excellent yields and ee values.
CHINESE CHEMICAL LETTERS
(2023)
Article
Chemistry, Organic
Yaowen Liu, Chunyu Han, Hongwei Shi, Alexandra V. Mackenroth, Linghua Zhang, Matthias Rudolph, Frank Rominger, A. Stephen K. Hashmi
Summary: A gold-catalyzed acyloxyalkynylation reaction was used to synthesize tetra-substituted enol ester 2-iodobenzoate derivatives in good yields at room temperature. The reaction is highly regioselective and can be easily scaled up to gram scale. Mechanistically, an Au(III) species plays a key role in an Au(I)/Au(III) redox cycle.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Xin Sun, Xiao-Yan Bai, An-Zhen Li, Bi-Jie Li
Summary: The study presents an iridium-catalyzed asymmetric hydroalkenylation method, allowing efficient construction of products with allylic stereocenters.
Article
Chemistry, Multidisciplinary
Nina F. C. Ritchie, Adam J. Zahara, Sidney M. Wilkerson-Hill
Summary: In this study, we report the divergent reactivity of 2,2-dialkyl-3-(E)-alkenyl N-tosylhydrazones under Pd-catalyzed cross-coupling conditions, enabling the Z-selective synthesis of 3-aryl-1,4-dienes and gem-dialkyl vinylcyclopropanes. We found that the dialkylbiaryl phosphine ligand SPhos was the optimal ligand, producing skipped dienes with up to 83% isolated yield. The ratio of skipped diene to vinylcyclopropane depends on the structure of the alpha,alpha-disubstituted hydrazones and the aryl halide partner. Using sterically encumbered aryl bromides selectively provided trans-cyclopropane products with yields up to 69%. The reaction is stereospecific and stereoselective and occurs alongside a competing 1,2-alkenyl group migration pathway.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Xin Sun, En-Ze Lin, Bi-Jie Li
Summary: An iridium-catalyzed asymmetric hydroalkenylation reaction was reported in this study, where alpha-olefins were formed through selective cleavage of C-H bonds in enamides. The reaction exhibited high branch-selectivity and enantioselectivity, yielding trisubstituted alkenes with an allylic stereocenter.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Young Ho Kim, Dong Bin Kim, Su San Jang, So Won Youn
Summary: A Pd-catalyzed intramolecular allylic C-H amination method has been developed, allowing for the synthesis of diverse 1,3-X,N-heterocycles through selective allylic C-H cleavage and pi-allylpalladium formation. The use of substrates containing a labile allylic moiety and new catalytic systems overcomes significant challenges for achieving highly chemo- and regioselective allylic C-H amination.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jinjin Yang, Deping Kong, Hongli Wu, Zhen Shen, Hongyan Zou, Wentao Zhao, Genping Huang
Summary: In this study, the detailed reaction mechanism and selectivity origins of the palladium-catalyzed double-alkoxycarbonylation of 1,3-diynes were elucidated using density functional theory calculations. The computations revealed that the reaction proceeds via two consecutive catalytic cycles with the same mechanism, and the hydropalladation step determines the rate and regioselectivity of the reaction.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Tongxu Xiang, Yongze Liu, Qiaoling Xu, Kehan He, Fei Pan
Summary: In this study, we developed a novel synthetic method for regio- and diastereoselective difluoromethylthiolation of acrylamides using palladium catalysis. The reaction exhibited high efficiency and showed good functional group tolerances under mild conditions, allowing access to compounds with SCF2H-containing skeletons. Mechanistic studies and post-functionalization of the product reactions were also conducted to provide insights into the reaction mechanism.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Malavath Ratanlal, Jayaram Vankudoth, Gangavaram V. M. Sharma, Maruti A. Mali, Bertrand Carboni, Fabienne Berree, Subhash Ghosh
Summary: An efficient stereo-controlled synthesis method using sequential Suzuki-Miyaura coupling reactions from easily prepared 1-alkene-1,2-diboronic esters and alkynyl bromides to obtain enyne and enediyne derivatives is reported. The resulting enyne boronic esters were further subjected to Borono-Mannich and Suzuki coupling reactions independently to obtain a,ss-unsaturated aminoester and tri-substituted olefin derivatives, respectively. Additionally, divergent syntheses of triazole and cyclopropylboronate derivatives were also presented.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Ju-Song Yang, Ka Lu, Chen-Xiao Li, Zu-Hang Zhao, Fu-Min Zhang, Xiao-Ming Zhang, Yong-Qiang Tu
Summary: A nickel hydride-catalyzed regio- and enantioselective hydroalkylation reaction was developed to access a library of chiral beta- or gamma-branched aromatic N-heterocycles. This intriguing asymmetric transformation features excellent selectivities, step- and atom-economies, and generates two kinds of chiral products through one synthetic strategy. The possible reaction mechanism was extensively investigated using numerous control experiments and density functional theory calculations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Ju-Song Yang, Ka Lu, Chen-Xiao Li, Zu-Hang Zhao, Fu-Min Zhang, Xiao-Ming Zhang, Yong-Qiang Tu
Summary: A nickel hydride-catalyzed hydroalkylation reaction was developed for the synthesis of a library of chiral aromatic N-heterocycles. The reaction demonstrated excellent selectivities, step- and atom-economies, and resulted in two kinds of chiral products through one synthetic strategy. The possible reaction mechanism was extensively investigated using control experiments and density functional theory calculations.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Toshimichi Kobayashi, Soshi Nishino, Masahiro Miura, Koji Hirano
Summary: A copper-catalyzed silylamination reaction has been developed for the synthesis of β-silyl-α-amino acid derivatives, which are of great interest in medicinal and pharmaceutical chemistry. The use of a suitable chiral ligand enables asymmetric induction, leading to the formation of optically active compounds with high enantiomeric ratios.
Article
Chemistry, Organic
Takeshi Nanjo, Hikari Sada, Taisei Nagaya, Yuri Maruo, Yoshiji Takemoto
Summary: In this study, a cationic rhodium catalyst and methyl trifluoroborate salt were used to achieve the stereoselective formation of beta,beta-disubstituted dehydroamino acids (ΔAAs) in peptides. This method allowed the direct installation of an alkyl group on a beta-monosubstituted ΔAA in the peptide chain, leading to the successful synthesis of both isomers of dehydroisoleucine, which is an important yet usually inaccessible ΔAA.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Jyun-Jia Tsai, Yen-Hsiang Huang, Chih-Ming Chou
Summary: A carboxylate-assisted palladium-catalyzed Mizoroki-Heck arylation of electron-deficient internal alkenes was developed, utilizing free carboxylic acid as a directing group. The synthetic application demonstrated the potential of this method in decarboxylative aromatization and iodolactonization reactions.
Article
Chemistry, Organic
Qin Wang, Yan Shi, Xiaoli Huang, Yongzhuang Wang, Jiao Jiao, Yuhai Tang, Jing Li, Silong Xu, Yang Li
Summary: A highly efficient Ru(II)-catalyzed regio- and stereospecific hydro-oxycarbonylation reaction has been developed for unsymmetrical internal alkynes bearing a difunctional 2-pyridyloxy directing group with carboxylic acids. This reaction provides allylic (Z)-enol esters in good to excellent yields with a broad substrate scope under mild conditions. The difunctional directing group can be diversely derivatized, particularly allowing for allylic substitution with various nucleophiles to afford beta-functionalized (Z)-enol esters without directing groups.
