235083-55-3Relevant articles and documents
One-Pot Transformation of Ketoximes into Optically Active Alcohols and Amines by Sequential Action of Laccases and Ketoreductases or ω-Transaminases
Correia Cordeiro, Raquel S.,Ríos-Lombardía, Nicolás,Morís, Francisco,Kourist, Robert,González-Sabín, Javier
, p. 1272 - 1277 (2019/01/24)
An enzymatic one-pot process for asymmetric transformation of prochiral ketoximes into alcohols or amines was developed by sequential coupling of a laccase-catalyzed deoximation either with a ketone reduction (ketoreductase, KRED) or bioamination (ω-transaminase, ω-TA) in aqueous medium. An accurate selection of biocatalysts provided the corresponding products in excellent enantiomeric excesses and overall conversions ranging from 83 to >99 % for alcohols and 70 to >99 % for amines. Likewise, the employment of exclusively 1 % (w/w) of Cremophor, a polyethoxylated castor oil, as co-solvent enabled to reach concentrations up to 100 mM in the chiral alcohols cascade.
Chemoenzymatic one-pot synthesis in an aqueous medium: combination of metal-catalysed allylic alcohol isomerisation-asymmetric bioamination
Ríos-Lombardía, Nicolás,Vidal, Cristian,Cocina, María,Morís, Francisco,García-álvarez, Joaquín,González-Sabín, Javier
supporting information, p. 10937 - 10940 (2015/06/30)
The ruthenium-catalysed isomerisation of allylic alcohols was coupled, for the first time, with asymmetric bioamination in a one-pot process in an aqueous medium. In the cases involving prochiral ketones, the ω-TA exhibited excellent enantioselectivity, identical to that observed in the single step. As a result, amines were obtained from allylic alcohols with high overall yields and excellent enantiomeric excesses.
Synthesis of highly enantiomerically enriched amines by the diastereoselective addition of triorganozincates to N-(tert-butanesulfinyl)imines
Almansa, Raquel,Guijarro, David,Yus, Miguel
experimental part, p. 2484 - 2491 (2009/04/11)
The reaction of triorganozincates with (R)-N-(tert-butanesulfinyl) imines gives the expected α-branched sulfinamides in good to excellent yields with diastereomeric ratios of up to 98:2. The N-sulfinyl group of the products can be easily removed by acidic treatment, affording the corresponding chiral primary amines in enantiomeric excesses of up to 96%. The reactivity and the selectivity shown by the triorganozincates are different from the ones observed with the corresponding Grignard reagents, which allows, in several cases, the preparation of both enantiomers of an amine from the same imine substrate. When mixed triorganozincates are used, one can take advantage of the slow transfer rate of the methyl group to use it as a non-transferable one. Both aromatic and aliphatic aldimines, as well as activated ketimines, are good substrates for these addition reactions.
Asymmetric reduction of oxime ethers promoted by chiral spiroborate esters with an O3BN framework
Chu, Yunbo,Shan, Zixing,Liu, Dejun,Sun, Nannan
, p. 3998 - 4001 (2007/10/03)
Enatioselective reduction of oxime ethers promoted by chiral spiroborate esters with an O3BN framework is reported for the first time. In the presence of (R,S)-1, 11 aralkyloxime ethers are reduced by borane-THF at 0-5 °C to give (S)-1-aralkylamine in high yield and excellent enatiomeric excess (up to 98% ee). Influence of reaction conditions on the enantioselectivity of the reduction is investigated, and a possible mechanism of the catalytic reduction is suggested.
Enantioselective addition of diethylzinc to N-diphenylphosphinoylimines employing N,N-dialkyl-1,2-diphenyl-2-aminoethanols as chiral ligands
Zhang, Xiaomei,Gong, Liuzhu,Mi, Aiqiao,Cui, Xin,Jiang, Yaozhong,C. K. Choi, Michael,S. C. Chan, Albert
, p. 6369 - 6372 (2007/10/03)
By fine-tuning the substituents on the nitrogen of (1S,2R) and (1R,2S)-1,2-diphenyl-2-aminoethanols, a chiral ligand 2b was obtained, which showed excellent enantioselectivity, with up to 94% e.e, for the asymmetric addition of diethylzinc to N-diphenylphosphinoylimines 1. In one example, the optically active amide 3c was converted into a new amine 5 with 98% e.e. by a reaction sequence involving Suzuki coupling and hydrolysis without racemization.
Further enantioselective syntheses of α-arylalkanamines via intermediate addition of Grignard reagents to a chiral hydrazone derived from (R)-(-)-2-aminobutan-1-ol
Bataille, Patricia,Paterne, Michel,Brown, Eric
, p. 1579 - 1588 (2007/10/03)
Reaction of various aromatic aldehydes with the chiral hydrazine (R)-(- )-2, derived from 2-aminobutan-1-ol (R)-(-)-1, gave the corresponding hydrazones 5-12. Enantioselective addition of EtMgBr or n-BuMgBr to 5-8 gave the trisubstituted hydrazines 13a-f
A convenient synthesis of the paclitaxel side-chain via a diastereoselective Staudinger reaction
Brown, Stephen,Jordan, Allan M.,Lawrence, Nicholas J.,Pritchard, Robin G.,McGown, Alan T.
, p. 3559 - 3562 (2007/10/03)
The N-benzylidene dexivative of (S)-(-)-1-(p-mathoxyphenyl)propyl-1- amine, obtained by a new resolution procedure, exhibits moderate selectivity in the reaction with 2-acetoxyketene; the (S)-(-)-1-(p-methoxyphenyl)propyl group can be oxidatively cleaved from the resultant β-lactam, an important precursor for taxane semi-synthesis.
