283157-03-9Relevant academic research and scientific papers
Enantioselective Strecker-type reaction promoted by polymer-supported bifunctional catalyst
Nogami, Hiroyuki,Matsunaga, Shigeki,Kanai, Motomu,Shibasaki, Masakatsu
, p. 279 - 283 (2001)
The JandaJEL-supported bifunctional catalyst 3 (10 mol%) promoted the Strecker-type reaction of aromatic and α,β-unsaturated imines in excellent yields with 83-87% ee in the presence of 'BuOH (110 mol%). The reactivity of 3 was comparable to the homogeneous analogue 1, and 3 could be recycled at least four times.
Highly enantioselective titanium-catalyzed cyanation of imines at room temperature
Seayad, Abdul Majeed,Ramalingam, Balamurugan,Yoshinaga, Kazuhiko,Nagata, Takushi,Chai, Christina L. L.
supporting information; experimental part, p. 264 - 267 (2010/03/24)
(Figure presented) A highly active and enantioselective titanium-catalyzed cyanatlon of imines at room temperature Is described. The catalyst used Is a partially hydrolyzed titanium alkoxide (PHTA) precatalyst together with a readily available N-salicyl-β-aminoalcohol ligand. Up to 98% ee was obtained with quantitative yields In 15 min of reaction time using 5 mol % of the catalyst. Various N-protecting groups such as benzyl, benzhydryl, Boc, and PMP are tolerated.
Chiral lanthanum(III)-binaphthyldisulfonate complexes for catalytic enantioselective strecker reaction
Hatano, Manabu,Hattori, Yasushi,Furuya, Yoshiro,Ishihara, Kazuaki
supporting information; experimental part, p. 2321 - 2324 (2009/10/02)
A catalytic enantioselective Strecker reaction catalyzed by novel chiral lanthanum(III)-binaphthyl disulfonate complexes was developed. The key to promoting the reactions was a semistoichiometric amount of AcOH or i-PrCO2H, which takes advantage of HCN ge
A catalytic asymmetric Strecker-type reaction promoted by Lewis acid-Lewis base bifunctional catalyst
Takamura,Hamashima,Usuda,Kanai,Shibasaki
, p. 1586 - 1592 (2007/10/03)
A general asymmetric Strecker-type reaction is reported, catalyzed by the Lewis acid-Lewis base bifunctional catalyst 1. The reaction of trimethylsilyl cyanide (TMSCN) with various fluorenyl imines, including n-aldimines and α,β-unsaturated imines, proceeds with good to excellent enantioselectivities in the presence of a catalytic amount of phenol as additive (20 mol%) (catalytic system 1). The products were successfully converted to the corresponding amino acid derivatives in high yields without loss of enantiomeric purity. Furthermore, hydrogenation or dihydroxylation of the products from α,β-unsaturated imines afforded saturated or functionalized aminonitriles also without loss of enantiomeric purity. The absolute configuration of the products and a control experiment using catalyst 2 supported the proposed dual activation of the imine and TMSCN by the Lewis acid (Al) and the Lewis base moiety (phosphine oxide) of 1. From the mechanistic studies including kinetic and NMR experiments of the catalytic species, the role of PhOH seems to be a proton source to protonate the anionic nitrogen of the intermediate. Specifically, we have found that TMSCN is more reactive than HCN in this catalytic system, probably due to the activation ability of the phosphine oxide moiety of 1 toward TMSCN. This fact prompted us to develop the novel catalytic system 2, consisting of 1 (9 mol%), TMSCN (20 mol%) and HCN (1.2 mol eq). This new system afforded comparable results with obtained by system 1 (1 (9 mol%)-TMSCN (2 mol eq)-PhOH (20 mol%)).
