115826-93-2Relevant academic research and scientific papers
Mechanism of NHC-Catalyzed Conjugate Additions of Diboron and Borosilane Reagents to α,β-Unsaturated Carbonyl Compounds
Wu, Hao,Garcia, Jeannette M.,Haeffner, Fredrik,Radomkit, Suttipol,Zhugralin, Adil R.,Hoveyda, Amir H.
, p. 10585 - 10602 (2015/09/28)
Broadly applicable enantioselective C-B and C-Si bond-forming processes catalyzed by an N-heterocyclic carbene (NHC) were recently introduced; these boryl and silyl conjugate addition reactions (BCA and SCA, respectively), which proceed without the need f
An Insoluble Copper(II) Acetylacetonate-Chiral Bipyridine Complex that Catalyzes Asymmetric Silyl Conjugate Addition in Water
Kitanosono, Taku,Zhu, Lei,Liu, Chang,Xu, Pengyu,Kobayashi, Shu
supporting information, p. 15422 - 15425 (2015/12/26)
Acicular purplish crystals were obtained from Cu(acac)2 and a chiral bipyridine ligand. Although the crystals were not soluble, they nevertheless catalyzed asymmetric silyl conjugate addition of lipophilic substrates in water. Indeed, the reactions proceeded efficiently only in water; they did not proceed well either in organic solvents or in mixed water/organic solvents in which the catalyst/substrates were soluble. This is in pronounced contrast to conventional organic reactions wherein the catalyst/substrates tend to be in solution. Several advantages of the chiral Cu(II) catalysis in water over previously reported catalyst systems have been demonstrated. Water is expected to play a prominent role in constructing and stabilizing sterically confined transition states and accelerating subsequent protonation to achieve high yields and enantioselectivities.
Enantioselective conjugate silyl additions to cyclic and acyclic unsaturated carbonyls catalyzed by Cu complexes of chiral N-heterocyclic carbenes
Lee, Kang-Sang,Hoveyda, Amir H.
supporting information; experimental part, p. 2898 - 2900 (2010/05/01)
(Figure Presented) An efficient Cu-catalyzed protocol for enantioselective addition of a dimethylphenylsilanyl group to a wide range of cyclic and acyclic unsaturated ketones, esters, acrylonitriles, and α,β,γ,σ- dienones is disclosed. Reactions are performed in the presence of 1-2 mol % of commercially available and inexpensive CuCl, a readily accessible monodentate imidazolinium salt, and commercially available (dimethylphenylsilyl) pinacolatoboron. Cu-catalyzed enantioselective conjugate additions proceed to completion within only 2 h to afford the desired silanes in 87-97% yield and 90:10-99:1 enantiomeric ratio (er). Use of a proton source (e.g., MeOH) is not required; accordingly, synthetically versatile α-silyl boron enolates can be obtained. The special utility of the present protocol, in comparison with the related catalytic enantioselective aldol and boronate conjugate additions, is discussed and illustrated through various functionalizations of the enantiomerically enriched Β-silylcarbonyls. Copyright
Cu-catalyzed asymmetric conjugate additions of dialkyl- and diarylzinc reagents to acyclic β-silyl-α,β-unsaturated ketones. Synthesis of allylsilanes in high diastereo- and enantiomeric purity
Kacprzynski, Monica A.,Kazane, Stephanie A.,May, Tricia L.,Hoveyda, Amir H.
, p. 3187 - 3190 (2008/02/11)
A readily available and simple (MW = 444.5 g/mol) valine-based chiral phosphine is used to promote highly efficient catalytic asymmetric conjugate additions of dialkyl- and diarylzinc reagents to acyclic β-silyl-α, β-unsaturated ketones. The catalytic asy
Catalytic asymmetric synthesis of β-hydroxy ketones by palladium-catalyzed asymmetric 1,4-disilylation of α,β-unsaturated ketones
Matsumoto, Yonetatsu,Hayashi, Tamio,Ito, Yoshihiko
, p. 335 - 346 (2007/10/02)
1,4-Disilylation of β,β-unsaturated ketones with 1,1-dichloro-1-phenyl-2,2,2-trimethyldisilane proceeded in the presence of phosphine-palladium catalysts in benzene. High enantio-selectivity (up to 92%) was observed in the disilylation with dichloro[(R)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl] palladium(II) as a catalyst (0.5 mol %). The disilylation products, 1-(trimethyisilyloxy)-3-(dichlorophenylsilyl)propenes, were readily converted into optically active α-unsubstituted or anti α-substituted β-(phenyldimethylsilyl) ketones, the oxidation of which gave the corresponding optically active β-hydroxy ketones in high yields.
