Article
Chemistry, Organic
Yangxu Chen, Bai Shi, Huiping Yin, Yinping Liu, Chenxia Yu, Kai Zhang, Tuanjie Li, Changsheng Yao
Summary: A photopromoted NHC catalyzed method for the asymmetric [4 + 2] annulation of saccharine-derived azadienes and alpha-diazoketones has been developed. This method utilizes readily available substrates and achieves the construction of vicinal tertiary and quaternary carbon stereocenters in moderate to good yields with excellent enantio- and diastereoselectivities.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Multidisciplinary
Sayaji Arjun More, Vikas Ashokrao Sadaphal, Tung-Chun Kuo, Mu-Jeng Cheng, Rai-Shung Liu
Summary: Two catalytic annulations of non-symmetric diarylketenes with thioalkynes are described using gold and phosphine catalysts respectively. Gold-pi-ketenes were generated from alpha-aryldiazo ketones, resulting in azulen-1-one derivatives. With the same reactants, the use of P(C6F5)(3) increased the yields of 1-naphthols significantly, showing complete regioselectivity.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Yuan-Yuan Gao, Chun-Lin Zhang, Lei Dai, You-Feng Han, Song Ye
Summary: The unprecedented dynamic kinetic resolution (DKR) of hemiaminals without alpha-hydrogen was developed via N-heterocyclic carbene catalyzed O-acylation, resulting in high yields of esters with good to high enantioselectivities.
Review
Chemistry, Multidisciplinary
Runjiang Song, Zhichao Jin, Yonggui Robin Chi
Summary: This review evaluates and summarizes the covalent activation of heteroatoms enabled by N-heterocyclic carbene (NHC) organic catalysts for enantioselective reactions. Sulfur, oxygen, and nitrogen atoms can be activated in this manner to construct chiral carbon-heteroatom bonds with high optical enantioselectivities. The key lies in the formation of intermediates covalently bound to the NHC catalyst, in which the heteroatom of the substrate is activated as a nucleophilic reactive site.
Article
Chemistry, Multidisciplinary
Niklas Radhoff, Constantin G. G. Daniliuc, Armido Studer
Summary: The design, synthesis, and application of benzene bioisosteres have been a subject of great interest in the past two decades. Recently, bicyclo[2.1.1]hexanes have been established as highly attractive bioisosteres for ortho- and meta-substituted benzenes. In this study, we present a mild, scalable, and transition-metal-free method for constructing highly substituted bicyclo[2.1.1]hexan-2-ones through Lewis acid-catalyzed (3+2)-cycloaddition of bicyclo[1.1.0]-butane ketones with disubstituted ketenes. The reaction exhibits high functional group tolerance, as evidenced by the successful synthesis of various 3-alkyl-3-aryl and 3,3-bisalkyl bicyclo[2.1.1]hexan-2-ones (26 examples, up to 89% yield). Additionally, postfunctionalization of the exocyclic ketone moiety is demonstrated.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Qi Xiong, Lu Xiao, Xiu-Qin Dong, Chun-Jiang Wang
Summary: In this study, an iridium-catalyzed cascade allylation/macrolactonization reaction was developed, which efficiently synthesizes chiral macrodiolides with excellent diastereoselectivities and enantioselectivities. This method is characterized by readily available substrates, high stereoselective control, and efficient synthetic steps.
Article
Chemistry, Multidisciplinary
Wangsheng Liu, Linrui Zhang, Xiaoyun Liao, Jiean Chen, Yong Huang
Summary: The NHC-catalyzed asymmetric [3+2] cyclization of benzoyl cyanides to homoenolate generated in situ from enals efficiently constructs a series of chiral cyclic compounds bearing vicinal quaternary stereocenters under mild reaction conditions. Representative large-scale and derivatization reactions of the chiral cyclic products demonstrate the potential synthetic utility of this protocol.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Jun Li, Scott R. Gilbertson
Summary: This study reports a diastereoselective [4 + 2] cycloisomerization of asymmetric allenyl dienes synthesized using Ma's method. These substrates undergo diastereoselective intramolecular rhodium catalyzed [4 + 2] cycloisomerization similar to thermal intramolecular Diels-Alder reactions, with diastereoselectivities ranging from 99:1 to 90:10 in most examples out of 29 presented.
Article
Chemistry, Organic
Rui-Hao Liu, Guo-Li Chai, Xiao Wang, Hong-Yu Deng, Junbiao Chang
Summary: The asymmetric 1,3-dipolar cycloaddition reaction of beta-trifluoromethyl alpha,beta-unsaturated ketone with N,N'-cyclic azomethine imines was developed using a (R)-3,3'-(3,5-(CF3)2-C6H3)2-BINOL-boron complex catalyst. The reaction efficiently produces N,N'-bicyclic pyrazolidine derivatives with a stereogenic carbon center containing CF3 motifs in high yields and excellent diastereo- and enantioselectivities.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Nana Ma, Lanxin Zhou, Yameng Li, Hao Wu, Shujun Li, Guisheng Zhang
Summary: The reaction mechanism of a Cu(I)-catalyzed [2 + 2 + 1] cycloaddition reaction for the synthesis of multisubstituted β-pyrrolinones was investigated using theoretical and computational chemistry. The calculated results suggest that ketene formed by the Wolff rearrangement of α-diazo-β-ketoester react with enamine formed by the addition of alkynes and amine to form a five-membered azaheterocycle. This process involves the formation of a six-membered ring intermediate and sequential isomerization, and the further dehydrogenation requires the assistance of solvent MeNO(2).
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Le-Song Wu, Yi Ding, Ye-Qiang Han, Bing-Feng Shi
Summary: The paper describes an asymmetric C-H activation strategy for accessing alpha,beta-stereospecific gamma-lactams in good yields with high enantio- and diastereoselectivities, serving as an effective supplement to existing strategies.
Article
Chemistry, Multidisciplinary
An Li, Li Ping Hu, Tao Yang, Zan Yang, Yu Liu, Li Jun Li, Ke Wen Tang, Cong Shan Zhou
Summary: The study developed a copper-catalyzed [4+1] cycloannulation reaction of 2-aminochalcones with ethyl 2-diazo-2-phenylacetates, allowing for the migration of the ester group and providing a simple and effective method for synthesizing various indole heterocyclic compounds. The reaction showed a wide substrate scope and good tolerance towards functional groups, with mechanistic studies revealing a step-by-step sequence involving carbine N-H insertion, intramolecular hydroxaldehyde-type condensation, and 1,2-acyl migration.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Yan Li, Lina Geng, Zhiyi Song, Zhiqiang Zhang
Summary: The mechanistic features and chemo- and stereoselectivities of the [4 + 2] cycloaddition between 2-bromo-2-enal and acylhydrazone catalyzed by a chiral N-heterocyclic carbene (NHC) catalyst were investigated using density functional theory calculations. The results were in agreement with experimental observations, and the origins of the stereoselectivity were revealed. The role of NHC was also investigated through global reactivity indexes analysis.
NEW JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Organic
Justin S. Lamb, Ryo Takashima, Yumiko Suzuki
Summary: This study proposed a method to synthesize alpha-amino ketones using N,N'-dipyridin-2-yl aminals, resulting in high yields of the desired compounds. Additionally, a direct route to N-Boc-protected alpha-amino ketones from N,N,N'-tris-Boc aminals was discovered with yields up to 73%.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Shilpa Barik, Sayan Shee, Rajesh G. Gonnade, Akkattu T. Biju
Summary: The NHC-organocatalyzed [3 + 3] annulation of 2-bromoenals with fi-oxodithioesters, resulting in the enantioselective synthesis of dihydrothiopyranones, is described. The chiral a,fi-unsaturated acylazoliums generated from 2-bromoenals and carbenes react smoothly with sulfur nucleophiles to afford the sulfur heterocycles with satisfactory yields/selectivity. The regioselective formation of dihydrothiopyranones over dihydropyranones is notable.
Article
Multidisciplinary Sciences
Yinghua Yu, Pushkin Chakraborty, Jinshuai Song, Lei Zhu, Chunsen Li, Xueliang Huang
NATURE COMMUNICATIONS
(2020)
Article
Chemistry, Organic
Xiaojian Ren, Lei Zhu, Yinghua Yu, Zhi-Xiang Wang, Xueliang Huang
Article
Chemistry, Organic
Jibing Liu, Lei Zhu, Wan Wan, Xueliang Huang
Review
Chemistry, Organic
Fulin Zhang, Luoting Xin, Yinghua Yu, Saihu Liao, Xueliang Huang
Summary: This review summarizes the significance and methods of transition-metal-catalyzed bridging C-H activation in chemical synthesis, with a particular focus on the role of alkenes, alkynes, and metal carbenes as intermediates in the activation process.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Physical
Luoting Xin, Wan Wan, Yinghua Yu, Qiuling Wan, Liyao Ma, Xueliang Huang
Summary: The study presents a novel method for the synthesis of pyridoisoquinolinone derivatives using pyridotriazoles and o-bromo/pseudohalo benzaldehydes. This method is efficient and provides a rapid route to prepare protoberberine-type alkaloids. The pyridotriazole plays a dual role in promoting C-H bond functionalization and constructing the polycyclic system through pyridine dearomatization.
Article
Chemistry, Applied
Liyao Ma, Yinghua Yu, Luoting Xin, Lei Zhu, Jiajin Xia, Pengcheng Ou, Xueliang Huang
Summary: A novel synthesis method is described in this work, where acylsilanes are coupled with aldehydes under visible light to produce alpha-hydroxyketones without the need for a photosensitizer or any other additives. The reaction can occur at ambient temperature with low energy visible light irradiation.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Qiuling Wan, Luoting Xin, Jian Zhang, Xueliang Huang
Summary: This study describes a gold-catalysed cycloisomerization of 1,5-diynes, providing a selective access to 1,3,4-trisubstituted pyrroles. The cationic gold catalyst activates the ynamide moiety, initiating the cycloisomerization to produce the pyrrole core. Water acts as an external nucleophile to trap the vinyl cationic species, leading to the formation of 1,3,4-trisubstituted pyrroles with high selectivity.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Chemistry, Organic
Ryan T. Kenny, Fei Liu
Summary: A robust synthesis of Soai-type pyrimidine aldehydes was achieved by controlled formation and quenching of a lithiated pyrimidine intermediate. The optimized rate of n-BuLi addition synchronized with the addition to ethyl formate, resulting in consistently high yields of 2-alkylpyrimidinecarboxaldehydes, which can be used in autocatalysis or as functionalized synthons.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jinling Liu, Yinghua Yu, Xueliang Huang
Summary: Deuterated compounds are important in pharmaceutical chemistry and the selective incorporation of deuterium atoms onto pharmacophore-containing compounds is of great interest. In this study, a concise method for constructing deuterated dibenzo-fused epsilon-lactones and epsilon-lactams through Pd-catalyzed carbene bridging C-D bond activation strategy was described. Deuterated ortho-bromobenzaldehydes were readily available reactants and deuterium atoms were selectively incorporated at the dibenylic position with high deuterated ratio.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Jiajin Xia, Jibing Liu, Yinghua Yu, Jian Zhang, Xueliang Huang
Summary: This study presents an unprecedented gold-catalyzed oxidative Buchner-type cyclopropanation, allowing the cycloisomerization of diynamides and the synthesis of diverse N-heterocyclic products with challenging structural skeletons.
Article
Chemistry, Organic
Pengcheng Ou, Lei Zhu, Yinghua Yu, Liyao Ma, Xueliang Huang
Summary: In this study, a Xantphos-containing dinuclear palladium complex was used to catalyze the geminal aminoallylation of diazocarbonyl compounds, providing a selective synthesis of various quaternary alpha-amino esters. The reaction did not proceed through direct N-H insertion, allylic alkylation of amino nucleophiles, or diene formation. Mechanistic investigations indicated that a relayed pathway via allylation or a [2,3]-sigmatropic rearrangement was unlikely.
Article
Chemistry, Multidisciplinary
Mingruo Ding, Pengcheng Ou, Xuening Li, Yinghua Yu, Mengmeng Niu, Yongjian Yang, Yewei Huang, Zhi-Xiang Wang, Xueliang Huang
Summary: Through space palladium/hydrogen shift is an efficient strategy for selective functionalization of a specific remote C-H bond. This study investigates the relatively less explored 1,5-Pd/H shift pattern between a vinyl and an acyl group, leading to the rapid synthesis of 5-membered-dihydrobenzofuran and indoline derivatives. The study also reveals a trifunctionalization of a phenyl ring through 1,5-palladium migration relayed decarbonylative Catellani type reaction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Jiajin Xia, Baolong Zhu, Qiuling Wan, Yinghua Yu, Shenlin Huang, Jian Zhang, Xueliang Huang
Summary: Transition metal-catalyzed divergent synthesis through alternation of the catalyst is demonstrated, providing an operationally simple way to access different valuable products from the same reactants. A gold-catalyzed cascade reaction of conjugated diynamides with allylic alcohols is described, giving selectively substituted allenes and furans by varying the catalysts. Mechanistic studies reveal a [3,3]-sigmatropic rearrangement and an intramolecular Himbert arene/allene Diels-Alder cycloaddition as additional reaction sequences to access dearomatized products with bicyclo[2,2,2]octadiene core.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Fulin Zhang, Ruihua Zhao, Lei Zhu, Yinghua Yu, Saihu Liao, Zhi-Xiang Wang, Xueliang Huang
Summary: The formation of a five membered palladacycle enables the selective activation of a proximal C-H bond in the aldehyde moiety and the construction of a valuable isoindolinone framework. Variation of the reaction conditions allows for the selective formation of three types of isoindolinones. Mechanistic studies provide insights into the reaction pathways, and the synthetic potential of this methodology is demonstrated through the concise routes to key intermediates of various compounds.
CELL REPORTS PHYSICAL SCIENCE
(2022)
Article
Chemistry, Organic
Wan Wan, Jibing Liu, Xueliang Huang
Summary: A novel approach to synthesizing 4-oxo-but-2-ynamides through gold-catalyzed selective oxidation of 1,3-diynamides has been developed. The products possess activated C-C triple bond and serve as versatile building blocks in synthetic community. The method provides a range of 4-oxo-but-2-ynamide derivatives in moderate to high yields, with the absence of traditional 1,2-dicarbonyl type products.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2021)
