1333225-65-2Relevant academic research and scientific papers
Synthesis of planar chiral imidazo[1,5-a]pyridinium salts based on [2.2]paracyclophane for asymmetric β-borylation of enones
Hong, Bing,Ma, Yudao,Zhao, Lei,Duan, Wenzeng,He, Fuyan,Song, Chun
, p. 1055 - 1062 (2011)
Novel planar chiral pseudo-geminal and pseudo-ortho-oxazoline substituted [2.2]paracyclophanyl imidazo[1,5-a]pyridinium triflates were synthesized. During the synthesis of a pseudo-ortho imidazo[1,5-a]pyridinium triflate based on [2.2]paracyclophane, the
Cellulosic CuI Nanoparticles as a Heterogeneous, Recyclable Catalyst for the Borylation of α,β-Unsaturated Acceptors in Aqueous Media
Zhou, Lijie,Han, Biao,Zhang, Yaoyao,Li, Bojie,Wang, Liansheng,Wang, Jianying,Wang, Xianbao,Zhu, Lei
, p. 3220 - 3229 (2021/03/06)
Abstract: We have demonstrated that cellulosic CuI nanoparticles could perform as an efficient heterogeneous catalyst for the synthesis of useful organoboron compounds. Desired β-borylation products were all obtained in good to excellent yields under mild
Configuration Sampling With Five-Membered Atropisomeric P,N-Ligands
Aponick, Aaron,Dahiya, Gaurav,Pappoppula, Mukesh
supporting information, p. 19604 - 19608 (2021/08/13)
Here we report a strategy for the systematic variation of atropisomeric C1-symmetric P,N ligands to incrementally change the position of the groups within the chiral pocket without modifying their steric parameters. More specifically, the effec
Cascade Reaction by Chemo- and Biocatalytic Approaches to Obtain Chiral Hydroxy Ketones and anti 1,3-Diols
Gandolfi, Raffaella,Facchetti, Giorgio,Christodoulou, Michael S.,Fusè, Marco,Meneghetti, Fiorella,Rimoldi, Isabella
, p. 393 - 400 (2018/06/04)
A chemo- and biocatalytic cascade approach was applied for the stereoselective synthesis of hydroxy ketones and the corresponding 1,3-diols. A new class of tridentate N,N,O ligands was used with copper(II) complexes for the asymmetric β-borylation of α,β-unsaturated compounds. The complex containing ligand L5 emerged as the best performer, and it gave the organoborane derivatives with good ee values. The corresponding keto–alcohol compounds were then bioreduced by yeasts. The biotransformation set up with Rhodotorula rubra allowed (R)-keto–alcohols and (S,S)-diols to be obtained with up to 99 % ee and up to 99 % de in favor of the anti enantiomers.
Well-Defined Chiral Copper NHC Complex in the Asymmetric Conjugated β-Borylation and One-Pot Metathesis-Asymmetric β-Borylation Reactions
Jana, Anupam,Trzybiński, Damian,Wo?niak, Krzysztof,Grela, Karol
, p. 891 - 897 (2018/01/27)
Highly stereoselective conjugate β-borylation, using a new chiral NHC-based copper catalyst, has been achieved. The chiral NHC copper complex was prepared in gram scale and showed high enantioselectivity and activity (up to 10 000 turnovers at 100 ppm of catalyst loading). This method was employed in the synthesis of a chiral β-borylated ester from simple unconjugated alkenes though an unprecedented one-pot cross metathesis-asymmetric borylation sequence.
Synthesis of fluorine-substituted [2.2]paracyclophane-based carbene precursors for copper-catalyzed enantioselective boration of α,β-unsaturated ketones
Wang, Linyong,Ye, Meng,Wang, Lei,Duan, Wenzeng,Song, Chun,Ma, Yudao
, p. 54 - 61 (2017/01/10)
Fluorine-substituted [2.2]paracyclophane-based carbene precursors have been successfully synthesized and applied to copper-catalyzed asymmetric β-boration of α,β-unsaturated ketones. Fluorination of the planar chiral carbenes has a beneficial impact on th
Synthesis and application of a dual chiral [2.2]paracyclophane-based N-heterocyclic carbene in enantioselective β-boration of acyclic enones
Wang, Lei,Chen, Zhen,Ma, Manyuan,Duan, Wenzeng,Song, Chun,Ma, Yudao
, p. 10691 - 10698 (2015/11/17)
An enantioselective conjugate addition of boron to α,β-unsaturated ketones catalysed by either a N-heterocyclic carbene or a copper-carbene complex generated in situ from a new chiral bicyclic triazolium based on [2.2]paracyclophane is presented. The dual
Heterogeneous versus homogeneous copper(II) catalysis in enantioselective conjugate-addition reactions of boron in water
Kitanosono, Taku,Xu, Pengyu,Kobayashi, Shu
supporting information, p. 179 - 188 (2014/01/06)
We have developed CuII-catalyzed enantioselective conjugate-addition reactions of boron to α,β-unsaturated carbonyl compounds and α,β,γ,δ-unsaturated carbonyl compounds in water. In contrast to the previously reported CuI catalysis that required organic solvents, chiral CuII catalysis was found to proceed efficiently in water. Three catalyst systems have been exploited: cat. 1: Cu(OH)2 with chiral ligand L1; cat. 2: Cu(OH)2 and acetic acid with ligand L1; and cat. 3: Cu(OAc)2 with ligand L1. Whereas cat. 1 is a heterogeneous system, cat. 2 and cat. 3 are homogeneous systems. We tested 27 α,β-unsaturated carbonyl compounds and an α,β-unsaturated nitrile compound, including acyclic and cyclic α,β-unsaturated ketones, acyclic and cyclic β,β- disubstituted enones, acyclic and cyclic α,β-unsaturated esters (including their β,β-disubstituted forms), and acyclic α,β-unsaturated amides (including their β,β-disubstituted forms). We found that cat. 2 and cat. 3 showed high yields and enantioselectivities for almost all substrates. Notably, no catalysts that can tolerate all of these substrates with high yields and high enantioselectivities have been reported for the conjugate addition of boron. Heterogeneous cat. 1 also gave high yields and enantioselectivities with some substrates and also gave the highest TOF (43 200 h-1) for an asymmetric conjugate-addition reaction of boron. In addition, the catalyst systems were also applicable to the conjugate addition of boron to α,β,γ, δ-unsaturated carbonyl compounds, although such reactions have previously been very limited in the literature, even in organic solvents. 1,4-Addition products were obtained in high yields and enantioselectivities in the reactions of acyclic α,β,γ,δ-unsaturated carbonyl compounds with diboron 2 by using cat. 1, cat. 2, or cat. 3. On the other hand, in the reactions of cyclic α,β,γ,δ-unsaturated carbonyl compounds with compound 2, whereas 1,4-addition products were exclusively obtained by using cat. 2 or cat. 3, 1,6-addition products were exclusively produced by using cat. 1. Similar unique reactivities and selectivities were also shown in the reactions of cyclic trienones. Finally, the reaction mechanisms of these unique conjugate-addition reactions in water were investigated and we propose stereochemical models that are supported by X-ray crystallography and MS (ESI) analysis. Although the role of water has not been completely revealed, water is expected to be effective in the activation of a borylcopper(II) intermediate and a protonation event subsequent to the nucleophilic addition step, thereby leading to overwhelmingly high catalytic turnover. Copyright
Enantioselective β-boration of acyclic enones by a [2.2]paracyclophane-based N-heterocyclic carbene copper(I) catalyst
Zhao, Lei,Ma, Yudao,He, Fuyan,Duan, Wenzeng,Chen, Jianqiang,Song, Chun
, p. 1677 - 1681 (2013/03/28)
A new planar and centrally chiral bicyclic 1,2,4-triazolium salt has been synthesized from [2.2]paracyclophane and phenylglycinol. The N-heterocyclic carbene (NHC) copper(I) complex generated in situ by the reaction of the triazolium salt and Cu2/su
Asymmetric β-boration of α,β-unsaturated carbonyl compounds with chiral Rh[bis(oxazolinyl)phenyl] catalysts
Toribatake, Kenji,Zhou, Li,Tsuruta, Ayae,Nishiyama, Hisao
, p. 3551 - 3560 (2013/05/08)
Chiral rhodium[bis(oxazolinyl)phenyl] complexes exhibited high catalytic activity for the β-boration of α,β-unsaturated esters, ketones, and amides with bis(pinacolato)diboron in the presence of sodium tert-butoxide to attain high enantioselectivity of up to 97%. The substrate scope and catalytic mechanism were discussed.
