620960-26-1Relevant articles and documents
Enantioselective construction of quaternary carbon centre catalysed by bifunctional organocatalyst
Liu, Tian-Yu,Long, Jun,Li, Bang-Jing,Jiang, Lin,Li, Rui,Wu, Yong,Ding, Li-Sheng,Chen, Ying-Chun
, p. 2097 - 2099 (2006)
A highly efficient organocatalytic method for the asymmetric Michael addition of α-substituted cyanoacetates to vinyl sulfones was investigated. It was observed that this reaction was synergistically promoted by readily available bifunctional thiourea-ter
Asymmetric direct vinylogous carbon-carbon bond formation catalyzed by bifunctional organocatalysts
Jiang, Lin,Zheng, Hong-Ting,Liu, Tian-Yu,Yue, Lei,Chen, Ying-Chun
, p. 5123 - 5128 (2007)
The bifunctional chiral thiourea-tertiary amine organocatalysts have been applied to a direct asymmetric vinylogous Michael addition of α,α-dicyanoolefins to nitroolefins with 2-10 mol % catalyst loadings. The electronic properties of the thiourea-based c
A simplified synthesis of Takemoto's catalyst
Berkessel,Seelig
, p. 2113 - 2115 (2009)
A facile two-step procedure for the preparation of Takemoto's catalyst is reported. The thiourea moiety was obtained by condensation of 3,5-bis(trifluoromethyl)aniline with phenyl chlorothioformate and in situ substitution of phenol by trans-1,2-diaminocy
Thiocarbonyl Surrogate via Combination of Sulfur and Chloroform for Thiocarbamide and Oxazolidinethione Construction
Tan, Wei,Wei, Jianpeng,Jiang, Xuefeng
supporting information, p. 2166 - 2169 (2017/04/27)
An efficient and practical thiocarbonyl surrogate via combination of sulfur and chloroform has been developed. A variety of thiocarbamides and oxazolidinethiones have been established, including chiral thiourea catalysts and chiral oxazolidinethione auxiliaries with high selectivity. Meanwhile, pesticides Diafenthiuron (an acaricide), ANTU (a rodenticide), and Chloromethiuron (an insecticide) were practically synthesized through this method in gram scale. Dicholorocarbene, as the key intermediate, was further confirmed via a carbene-trapping control experiment.
Directing the Activation of Donor–Acceptor Cyclopropanes Towards Stereoselective 1,3-Dipolar Cycloaddition Reactions by Br?nsted Base Catalysis
Blom, Jakob,Vidal-Albalat, Andreu,J?rgensen, Julie,Barl?se, Casper L.,Jessen, Kamilla S.,Iversen, Marc V.,J?rgensen, Karl Anker
, p. 11831 - 11835 (2017/09/20)
The first stereoselective organocatalyzed [3+2] cycloaddition reaction of donor-acceptor cyclopropanes is presented. It is demonstrated that by applying an optically active bifunctional Br?nsted base catalyst, racemic di-cyano cyclopropylketones can be activated to undergo a stereoselective 1,3-dipolar reaction with mono- and polysubstituted nitroolefins. The reaction affords functionalized cyclopentanes with three consecutive stereocenters in high yield and stereoselectivity. Based on the stereochemical outcome, a mechanism in which the organocatalyst activates both the donor-acceptor cyclopropane and nitroolefin is proposed. Finally, chemoselective transformations of the cycloaddition products are demonstrated.
Stereoselective reaction of 2-carboxythioesters-1,3-dithiane with nitroalkenes: An organocatalytic strategy for the asymmetric addition of a glyoxylate anion equivalent
Massolo, Elisabetta,Benaglia, Maurizio,Genoni, Andrea,Annunziata, Rita,Celentano, Giuseppe,Gaggero, Nicoletta
supporting information, p. 5591 - 5596 (2015/05/27)
An efficient organocatalytic methodology has been developed to perform the stereoselective addition of 2-carboxythioesters-1,3-dithiane to nitroalkenes. Under mild reaction conditions γ-nitro-β-aryl-α-keto esters with up to 92% ee were obtained, realizing a formal catalytic stereoselective conjugate addition of the glyoxylate anion synthon. The reaction products are versatile starting materials for further synthetic transformations; for example, the simultaneous reduction of the nitro group and removal of the dithiane ring was accomplished, allowing the preparation of a GABAB receptor agonist baclofen.
Asymmetric isomerization of ω-hydroxy-α,β-unsaturated thioesters into β-mercaptolactones by a bifunctional aminothiourea catalyst
Fukata, Yukihiro,Okamura, Takaaki,Asano, Keisuke,Matsubara, Seijiro
supporting information, p. 2184 - 2187 (2014/05/06)
We present a novel methodology for the asymmetric synthesis of β-mercaptolactones via isomerization of ω-hydroxy-α,β- unsaturated thioesters by means of a bifunctional aminothiourea catalyst. The catalyst interacts with the substrate through the cooperati
A reductive coupling strategy towards ripostatin A
Schleicher, Kristin D.,Jamison, Timothy F.
supporting information, p. 1533 - 1550 (2013/10/22)
Synthetic studies on the antibiotic natural product ripostatin A have been carried out with the aim to construct the C9-C10 bond by a nickel(0)-catalyzed coupling reaction of an enyne and an epoxide, followed by rearrangement of the resulting dienylcyclopropane intermediate to afford the skipped 1,4,7-triene. A cyclopropyl enyne fragment corresponding to C1-C9 has been synthesized in high yield and demonstrated to be a competent substrate for the nickel(0)-catalyzed coupling with a model epoxide. Several synthetic approaches toward the C10-C26 epoxide have been pursued. The C13 stereocenter can be set by allylation and reductive decyanation of a cyanohydrin acetonide. A mild, fluoride-promoted decarboxylation enables construction of the C15-C16 bond by an aldol reaction. The product of this transformation is of the correct oxidation state and potentially three steps removed from the targeted epoxide fragment.
The first catalytic, enantioselective aza-Henry reaction of an unactivated cyclic imine
Amarasinghe, Nilupa R.,Todd, Matthew H.,Turner, Peter
supporting information, p. 2954 - 2958,5 (2020/10/15)
The aza-Henry reaction is an efficient route to important chiral, vicinal diamines. Reports of the asymmetric version typically use electron-deficient acyclic imines. We report the first example of a catalytic, asymmetric aza-Henry reaction on an unfunctionalized cyclic imine that gives access to enantiopure diamine derivatives under experimentally straightforward conditions. The stereocentre is established through the initial nitromethane addition to the imine. The scalemic intermediate may be trapped through acylation, then crystallized. Copyright
Physical organic study of structure-activity-enantioselectivity relationships in asymmetric bifunctional thiourea catalysis: Hints for the design of new organocatalysts
Li, Xin,Deng, Hui,Zhang, Bo,Li, Jiuyuan,Zhang, Long,Luo, Sanzhong,Cheng, Jin-Pei
supporting information; experimental part, p. 450 - 455 (2010/06/22)
The first pKa scales for chiral thiourea catalysts and their correlations with the corresponding parameters of the bifunctional catalysis was reported. Twenty chiral thiourea-tertiary amine compounds were synthesized and electronic variations w
