1199-20-8Relevant articles and documents
Synthesis of 6-hydroxy-5,6-dihydro-2-pyrones and -pyridones by reaction of 4-aryl-6-trifluoromethyl-2-pyrones with water, hydrazine, and hydroxylamine
Usachev, Sergey A.,Usachev, Boris I.,Sosnovskikh, Vyacheslav Ya.
, (2017)
[Figure not available: see fulltext.] Reactions of 4-aryl-6-trifluoromethyl-2H-pyran-2-ones with sodium hydroxide followed by acidification provided the respective 6-hydroxy-5,6-dihydro derivatives, while the reactions of 4-aryl-6-trifluoromethyl-2H-pyran
Photocarboxylation in the Presence of Aromatic Amines and Carbon Dioxide
Ito, Yoshikatsu,Uozu, Yoshihiro,Matsuura, Teruo
, p. 562 - 564 (1988)
Phenylethylenes (1), biphenyl, and 1-methyl-2-phenylindole underwent carboxylation upon photolysis in the presence of aromatic amines (2) and carbon dioxide.
Synergistic N-Heterocyclic Carbene/Palladium-Catalyzed [3 + 2] Annulation of Vinyl Enolates with 1-Tosyl-2-vinylaziridine
Gao, Jian,Zhang, Jianming,Fang, Shuaishuai,Feng, Jie,Lu, Tao,Du, Ding
, p. 7725 - 7729 (2020/10/09)
The synergistic combination of N-heterocyclic carbene organocatalysis and transition-metal catalysis for a formal [3 + 2] annulation between 3-substituted but-2-enoates and 1-tosyl-2-vinylaziridine was developed. This cooperative strategy provides a facile and efficient access to various functionalized (E)-3-ethylidene-4-vinylpyrrolidin-2-ones in a regioselective and stereoselective manner. The preliminary asymmetric studies were also performed, which indicated a potential for enantioselective annulation of vinyl enolate intermediates with transition-metal-π-allyl species.
Construction of Multi-Substituted Benzenes via NHC-Catalyzed Reactions of Carboxylic Esters
Wu, Jichang,Mou, Chengli,Chi, Yonggui Robin
, p. 333 - 337 (2018/03/07)
A carbene-catalyzed ester activation reaction for the synthesis of multi-substituted benzenes is developed. Tetra-substituted benzene compounds are efficiently synthesized through this methodology. Compared with aldehyde substrates used in previous reports, the ester substrates used here are much more readily available and inexpensive. In addition, the TEMPO oxidant used here is more inexpensive than the quinones commonly used in related carbene-catalyzed reactions.
Pd-Catalyzed α-Selective C-H Functionalization of Olefins: En Route to 4-Imino-β-Lactams
Kong, Wei-Jun,Liu, Yue-Jin,Xu, Hui,Chen, Yan-Qiao,Dai, Hui-Xiong,Yu, Jin-Quan
, p. 2146 - 2149 (2016/03/05)
Pd-catalyzed α-olefinic C-H activation of simple α,β-unsaturated olefins has been developed. 4-imino-β-lactam derivatives were readily synthesized via activation of α-olefinic C-H bonds with excellent cis stereoselectivity. A wide range of heterocycles at the β-position are compatible with this reaction. The product of 4-imino-β-lactam derivatives can be readily converted to 2-aminoquinoline which exists extensively in pharmaceutical drugs and natural products.
Metal-Free Domino One-Pot Decarboxylative Cyclization of Cinnamic Acid Esters: Synthesis of Functionalized Indanes
Gopi Krishna Reddy, Alavala,Satyanarayana, Gedu
, p. 12212 - 12222 (2016/12/23)
Trifluoroacetic acid promoted unprecedented domino reaction for the synthesis of diverse indanes starting from simple cinnamic acid esters is described. Their formation can be explained via acid triggered decarboxylation of cinnamic acid esters and subsequent inter/intramolecular cyclization. Overall process involves in the intramolecular cleavage of two σ-bonds (C-O and C-C) and inter/intramolecular construction of two/one C-C σ-bond(s). Significantly, this protocol was successful without the aid of any metal salts.
N-Heterocyclic Carbene-Catalyzed Activation of Esters of N-Hydroxyphthalimide: A Highly Enantioselective Route to Chiral Dihydropyridinones Bearing an All Carbon Quaternary Stereogenic Center
Zhang, Zhiming,Zeng, Xiaofei,Xie, Danbo,Chen, Dongdong,Ding, Liyuan,Wang, Anna,Yang, Limin,Zhong, Guofu
, p. 5052 - 5055 (2015/11/03)
An N-heterocyclic carbene-catalyzed highly enantioselective [3 + 3] annulation reaction of N-hydroxyphthalimide (NHPI) 3,3-disubstituted acrylates and N-Ts ketimines was developed. In most cases, the desired chiral dihydropyridinone products bearing an all carbon quaternary stereogenic center could be obtained in good yields with excellent enantioselectivities (>99% ee's), which demonstrated the NHPI acrylates as a kind of excellent substrate in NHC-catalysis.
Organocatalytic enantioselective γ-aminoalkylation of unsaturated ester: Access to pipecolic acid derivatives
Xu, Jianfeng,Jin, Zhichao,Chi, Yonggui Robin
, p. 5028 - 5031 (2013/10/22)
The direct γ-carbon functionalization of α,β-unsaturated esters via N-Heterocyclic Carbene (NHC) catalysis is disclosed. This catalytically generated nucleophilic γ-carbon undergoes highly enantioselective additions to hydrazones. The resulting δ-lactam products can be readily transformed to optically enriched pipecolic acid derivatives.
Ruthenium-catalyzed asymmetric transfer hydrogenation of allylic alcohols by an enantioselective isomerization/transfer hydrogenation mechanism
Wu, Ruoqiu,Beauchamps, Marie G.,Laquidara, Joseph M.,Sowa Jr., John R.
supporting information; experimental part, p. 2106 - 2110 (2012/04/11)
Reducing hazards: A asymmetric transfer hydrogen reaction was developed to reduce prochiral allylic alcohols in high yield and excellent enantioselectivity (see example). Mechanistic studies indicate a novel enantioselective isomerization/transfer hydrogenation mechanism. This new reaction is much safer than high-pressure hydrogenation using H2 gas. Copyright
N-heterocyclic carbene-catalyzed cyclization of unsaturated acyl chlorides and ketones
Shen, Li-Tao,Shao, Pan-Lin,Ye, Song
, p. 1943 - 1948 (2011/10/13)
A straightforward synthesis of optically active trifluoromethyl dihydropyranones and spirocyclic oxindole-dihydropyranones has been realized by the chiral N-heterocyclic carbenes-catalyzed cyclization of α,β- unsaturated β-methylacyl chlorides with activated trifluoromethyl ketones or isatin derivatives. Copyright
