161972-08-3

Upstream product

• 946-33-8 2-benzylcyclohexan-1-one 
• 50648-70-9 trans-2-benzylidenecyclohexanol 
• 253609-29-9 (1'S,1''R,2R,5''R)-2-[phenyl-1'-(2''-azabicyclo[3.3.0]octane-2''-yl)methyl]cyclohexanone 
• 133616-97-4 (1S,5S)-2-(1-Cyclohexen-1-yl)-2-azabicyclo<3.3.0>octan 
• 133696-29-4 (1R,5R)-2-(1-Cyclohexen-1-yl)-2-azabicyclo<3.3.0>octan 
• 1125-99-1 1-(1-Cyclohexen-1-yl)pyrrolidine 
• 5682-83-7 (E)-2-benzylidenecyclohexanone 
• 187404-47-3 (R)-2-[1-phenyl-(E)-methylidene]-1-cyclohexanol 
• 253609-32-4 (1R,1'S,1''R,2R,5''R)-2-[phenyl-1'-(2''-azabicyclo[3.3.0]octane-2''-ylmethyl)methyl]cyclohexanol 

Relevant academic research and scientific papers

Direct Asymmetric Hydrogenation and Dynamic Kinetic Resolution of Aryl Ketones Catalyzed by an Iridium-NHC Exhibiting High Enantio- and Diastereoselectivity

A chiral iridium carbene-oxazoline catalyst is reported that is able to directly and efficiently hydrogenate a wide variety of ketones in excellent yields and good enantioselectivity (up to 93 % ee). Moreover, when using racemic α-substituted ketones, excellent diastereoselectivities were obtained (dr 99:1) by dynamic kinetic resolution of the in situ formed enolate. Overall, the herein described hydrogenation occurs under ambient conditions using low hydrogen pressures, providing a direct and atom efficient method towards chiral secondary alcohols.

Palladium-catalyzed asymmetric hydrogenation of 2-aryl cyclic ketones for the synthesis oftranscycloalkanols through dynamic kinetic resolution under acidic conditions

The first efficient palladium-catalyzed asymmetric hydrogenation of 2-aryl cyclic ketones has been described through dynamic kinetic resolution under acidic conditions, providing a facile access to chiraltranscycloalkanol derivatives with excellent enantioselectivities.

Isomerization-Asymmetric Hydrogenation Sequence Converting Racemic β-Ylidenecycloalkanols into Stereocontrolled β-Substituted Cycloalkanols Using a Ru Catalytic System with Dual Roles

Racemic β-ylidenecycloalkanols were transformed into the cis-β-substituted cycloalkanols with high enantio- and diastereoselectivities through an isomerization-asymmetric hydrogenation sequence with the (4,4′-bi-1,3-benzodioxole)-5,5′-diylbis[di(3,5-xylyl)phosphine (DM-Segphos)/2-dimethylamino-1-phenylethylamine (DMAPEN)-ruthenium(II) catalyst; such transformation hardly proceeded by single-step asymmetric hydrogenation. The reaction was usually carried out with a substrate-to-catalyst molar ratio of 500 under 4 to 10 atm of H2 to afford the products in cis/trans ratio up to 99:1 and 98% ee. Mechanistic experiments suggested that this catalytic system reversibly formed two reactive species, types (I) and (II), through a ruthenacyclic amide intermediate. The amide complex and allylic alcohol reacted to afford the allylic alkoxide complex with partial or full removal of diamine (type (I)), and this type (I) complex catalyzed isomerization of the allylic alcohols into the racemic α-substituted ketones. The RuH2 complex with chelation of diamine (type (II)) formed by reaction of the amide complex and hydrogen promoted asymmetric hydrogenation of racemic α-substituted ketone into the stereocontrolled β-substituted cycloalkanols through dynamic kinetic resolution. (Figure presented.).

Asymmetric reduction of prochiral cycloalkenones. The influence of exocyclic alkene geometry

The asymmetric reduction of a series of prochiral enones of general structure 1 using the Corey oxazaborolidine 2, leading to enantiomerically enriched allylic cycloalkanols 3 is described. The influence of alkene geometry on both the sense (R vs. S) and

Highly stereoselective synthesis of 1,3-aminoalcohols via Mannich reactions

Diastereoselective synthesis of β-amino ketones by a one-pot Mannich reaction and their subsequent reduction afforded sterically congested enantiomerically pure 1,3-aminoalcohols in high diastereoselectivity: dr up to >98:2 over two steps. The absolute configurations of the newly created stereogenic centers were assigned by NMR spectroscopy and chemical correlation.

Microbially-aided preparation of (S)-2-methoxycyclohexanone key intermediate in the synthesis of Sanfetrinem

(S) 2-Methoxycyclohexanone 1, useful intermediate in the synthesis of Sanfetrinem 2, is obtained from (S) α-benzylidene cyclohexanol 4, derived from the ketone 3 through a short sequence involving as key step yeast reduction of the carbonyl group. The (R) enantiomer of 1 is similarly accessible from the (R) enantiomer of 4 obtained either upon Candida lipolytica-mediated reduction of 3 or from (R,S)-4 by porcine pancreatic lipase catalyzed acetylation with vinyl acetate. Also the saturated carbinols 7 and 8, which accompany 4 in the microbial reduction of 3, are converted into 1 through unexceptional steps. Nocardia opaca, Pichia etchelsii and Mucor subtilissimus provide from 3 upon reduction (S)-configurated 4, 7 and 8 possessing moderate-high ee values.