19169-94-9Relevant academic research and scientific papers
Copper-Photocatalyzed Contra-Thermodynamic Isomerization of Polarized Alkenes
Bouillon, Jean-Philippe,Brégent, Thibaud,Poisson, Thomas
, p. 7688 - 7693 (2020/10/09)
The contra-thermodynamic isomerization of α- and β-substituted cinnamate derivatives catalyzed by the Cu(OAc)2/rac-BINAP complex under blue light irradiation is reported. The use of an oxazolidinone template, which favored the complexation of the copper catalyst to the substrate, allowed the E → Z isomerization of the catalytically formed chromophore under simple and robust reaction conditions in good to excellent ratios. The mechanism of this process based on the transient formation of a chromophore was also studied.
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.
Enantioselective epoxidation of β,β-disubstituted enamides with a manganese catalyst and aqueous hydrogen peroxide
Clarasó, Carlota,Vicens, Laia,Polo, Alfonso,Costas, Miquel
, p. 2430 - 2435 (2019/03/29)
Enantioselective epoxidation of β,β-disubstituted enamides with aqueous hydrogen peroxide and a novel manganese catalyst is described. Epoxidation is stereospecific and proceeds fast under mild conditions. Amides are disclosed as key functional groups to enable high enantioselectivity.
Chiral 1,3,2-Diazaphospholenes as Catalytic Molecular Hydrides for Enantioselective Conjugate Reductions
Miaskiewicz, Solène,Reed, John H.,Donets, Pavel A.,Oliveira, Caio C.,Cramer, Nicolai
, p. 4039 - 4042 (2018/03/13)
Secondary 1,3,2-diazaphospholenes have a polarized P?H bond and are emerging as molecular hydrides. Herein, a class of chiral, conformationally restricted methoxy-1,3,2-diazaphospholene catalysts is reported. We demonstrate their catalytic potential in asymmetric 1,4-reductions of α,β-unsaturated carbonyl derivatives, including enones, acyl pyrroles, and amides, which proceeded in enantioselectivities of up to 95.5:4.5 e.r.
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.
DMAP-Catalyzed [4 + 2] Cycloaddition of α,β-Unsaturated Carboxylic Acids with Ketones for Synthesis of α,β-Unsaturated δ-Lactones
Jin, Jinghai,Xu, Qinchang,Deng, Weiping
, p. 397 - 400 (2017/04/27)
The DMAP-catalyzed [4 + 2] cycloaddition of α,β-unsaturated carboxylic acids with ketones furnishing α,β-unsaturated δ-lactones in good yields (up to 80%) is described, which is the first example of remote γ-C(sp3)-H activation of α,β-unsaturated carboxylic acids facilitated by DMAP, a pyridine-based catalyst. Copyright
Pd(II)/Bipyridine-Catalyzed Conjugate Addition of Arylboronic Acids to α,β-Unsaturated Carboxylic Acids. Synthesis of β-Quaternary Carbons Substituted Carboxylic Acids
Liu, Rui,Yang, Zhenyu,Ni, Yuxin,Song, Kaixuan,Shen, Kai,Lin, Shaohui,Pan, Qinmin
, p. 8023 - 8030 (2017/08/14)
Pd(II)/bipyridine-catalyzed conjugate addition of arylboronic acids to α,β-unsaturated carboxylic acids (including β,β-disubstituted acrylic acids) was developed and optimized, which provided a mild and convenient method for the highly challenging synthesis of β-quaternary carbons substituted carboxylic acids.
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.
Synthesis of substituted nitroolefins: A copper catalyzed nitrodecarboxylation of unsaturated carboxylic acids
Rokade, Balaji V.,Prabhu, Kandikere Ramaiah
, p. 6713 - 6716 (2013/10/01)
A novel, mild and convenient method for the nitrodecarboxylation of substituted cinnamic acid derivatives to their nitroolefins is achieved using a catalytic amount of CuCl (10 mol%) and tert-butyl nitrite (2 equiv.) as a nitrating agent in the presence of air. This reaction provides a useful method for the synthesis of β,β-disubstituted nitroolefin derivatives, which are generally difficult to access from other conventional methods. Additionally, this reaction is selective as the E-isomer of the acid derivatives furnishes the corresponding E-nitroolefins. One more salient feature of the method is, unlike other methods, no metal nitrates or HNO3 are employed for the transformation.
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.
