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• 31887-88-4 N-(2-methylcyclohexylidene)-1-phenylmethanamine 
• 583-60-8 2-Methylcyclohexanone 
• 100-46-9 benzylamine 

Relevant academic research and scientific papers

First chemo- and stereoselective reduction of imines using trichlorosilane activated with N-formylpyrrolidine derivatives

Trichlorosilane activated with N-formylpyrrolidine derivatives was found to be an effective reagent for reduction of imines to amines. The reagent showed much higher selectivity toward imino groups than carbonyl groups. The reduction of imines using trichlorosilane activated with optically active N-formylproline derivatives gave enantiomerically enriched amines in moderate optical yields (up to 66% ee).

Hydride reagents for stereoselective reductive amination. An improved preparation of 3-endo-tropanamine

The reductive amination of substituted cyclohexanones with sodium triacyloxyborohydrides derived from NaBH4 and various carboxylic acids provides highly diastereoselective conversions to protected axial amines. This method was applied to the stereoselective preparation of 3-endo-tropanamine.

Asymmetric Reductive Amination of Cycloalkanones, 2. Synthesis and Absolute Configuration of 2-Substituted Cyclohexanamines

Asymmetric synthesis of 2-substituted cyclohexanamines from racemic cyclohexanones by means of reductive amination in a three-step procedure is described.Condensation of the ketones 5 with the optically active auxiliary amines 6 leads to the imines 7, which are hydrogenated to the secondary amines 8 with Raney nickel.Hydrogenolysis with palladium-on-charcoal yields the primary amines 9.With Raney nickel as catalyst the synthesis of the amines 8 and 9 runs with high chemical yield under complete diastereomeric and high grade enantiomeric control, respectively.Enantiomeric excess is determined via the diastereomeric acylamines 10 by means of HPLC.Stereochemical analysis including the absolute configuration of 8 and 9 is performed with 1H, 13C NMR spectroscopy, via the CD of the salicylidenes 11 and the X-ray spectrum of the amine 9c. - Reaction mechanism is investigated via the partially deuterated amine 13 to come up as a kinetically controlled asymmetric hydrogenation combined with a thermodynamically controlled transformation.

Stereoselective Reductions of Substituted Cyclohexyl and Cyclopentyl Carbon-Nitrogen ? Systems with Hydride Reagents

Reductions of 3- and 4-substituted cyclohexyl imines, iminium salts, and enamines (via iminium ions) with various hydride reagents reveal that while small reagents (NaBH4, NaBH3CN) favor axial approach as observed with the corresponding ketones, even moderately bulky reagents (i.e., acetoxyboranes) attack preferentially from the equatorial side.This is in direct contrast to the results observed for the same reagents with the corresponding ketones and is interpreted as implying that additional steric interactions induced by the nitrogen substituents encumber axial attack by substituted hydride reagents and force approach from the equatorial direction.The very bulky tri-sec-butylborohydride anion affords highly stereodiscriminating equatorial attack.Reductions of 2-alkylcyclohexyl and 2-alkylcyclopentyl imines and enamines also proceed with high stereoselectivity to give cis-2-alkyl cyclic amines with both hindered and unhindered reagents.This is interpreted to be the result of (1) augmented steric interactions between nitrogen substituents and equatorial 2-alkyl groups (1,3-allylic strain) which induces conformational changes to favor the axial 2-alkyl conformer and (2) hindrance toward equatorial approach by reagents induced by axial alkyl substituents.The result is that equatorial approach is favored with equatorial 2-alkyl conformers and preferential axial approach with axial 2-alkyl conformers, leading to stereoselective production of cis-2-alkylamines. trans-2-n-Propyl-4-tert-butylcyclohexanone is reduced by LiBH(sec-Bu)3 preferentially from the axial direction in contrast to the usual highly selective equatorial attack observed with other cyclohexanones.