71901-41-2Relevant articles and documents
In vitro biocatalytic pathway design: Orthogonal network for the quantitative and stereospecific amination of alcohols
Knaus, Tanja,Cariati, Luca,Masman, Marcelo F,Mutti, Francesco G.
supporting information, p. 8313 - 8325 (2017/10/19)
The direct and efficient conversion of alcohols into amines is a pivotal transformation in chemistry. Here, we present an artificial, oxidation-reduction, biocatalytic network that employs five enzymes (alcohol dehydrogenase, NADP-oxidase, catalase, amine dehydrogenase and formate dehydrogenase) in two concurrent and orthogonal cycles. The NADP-dependent oxidative cycle converts a diverse range of aromatic and aliphatic alcohol substrates to the carbonyl compound intermediates, whereas the NAD-dependent reductive aminating cycle generates the related amine products with >99% enantiomeric excess (R) and up to >99% conversion. The elevated conversions stem from the favorable thermodynamic equilibrium (K′eq = 1.88 × 1042 and 1.48 × 1041 for the amination of primary and secondary alcohols, respectively). This biocatalytic network possesses elevated atom efficiency, since the reaction buffer (ammonium formate) is both the aminating agent and the source of reducing equivalents. Additionally, only dioxygen is needed, whereas water and carbonate are the by-products. For the oxidative step, we have employed three variants of the NADP-dependent alcohol dehydrogenase from Thermoanaerobacter ethanolicus and we have elucidated the origin of the stereoselective properties of these variants with the aid of in silico computational models.
Enantioselective synthesis of 3-methylisochromans and determination of their absolute configurations by circular dichroism
Kerti, Gabor,Kurtan, Tibor,Illyes, Tuende-Zita,Koever, Katalin E.,Solyom, Sandor,Pescitelli, Gennaro,Fujioka, Naoko,Berova, Nina,Antus, Sandor
, p. 296 - 305 (2007/10/03)
Seven (S)-3-methylisochromans with different substitution patterns on their aromatic rings, and hence with different directions of their sum electric transition moments, were synthesized by ring-closure of optically active (S)-1-arylpropan-2-ol derivatives. The (S)-1-arylpropan-2-ols were obtained by kinetic resolution and their absolute configurations were determined with the aid of a zinc porphyrin tweezer and by Mosher's method. A systematic CD study of substituted isochroman derivatives revealed that, unlike in the cases of chiral tetralin and 2,3-dihydrobenzo[b]furan chromophores, the presence of achiral substituents of large spectroscopic moment (e.g., OMe) on the aromatic ring does not change the helicity rule of the "unsubstituted" isochroman chromophore: (P)/(M) helicity of the isochromen heteroring resulted in positive/negative 1Lb band Cotton effects (CE) regardless of the nature(s) and position(s) of the substituent(s). (S)-3-Methylisochromans were oxidized at C-1, allowing access to the corresponding dihydroisocoumarins, in which positive CE of the n→-π* transitions were correlated with (P) helicity and (S) absolute configuration. On DDQ-assisted oxidation, two trans-1-methoxy-3-methylisochrornan derivatives were prepared and used to study the effect of the axial benzylic C-1 methoxy group on the conformation of the heteroring and the 1Lb band CE. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Total Synthesis of Optically Active 17β-t-Butoxy-3-methoxy-7α- or -7β-18-dimethyl-1,3,5(10)-estratriene
Cai, Zu-Yun,Ni, Yuan,Sun, Jen-Kon,Yu, Xin-Di,Wang, Yan-Qiu
, p. 1277 - 1278 (2007/10/02)
In the preparation of 7-methyl-19-nor-steroids, a new method for the synthesis of key intermediates (10), which involves alkylation of the CD ring fragment (4) and subsequent hydrogenation, cyclization, and hydrogenation is described.
