68790-19-2

Upstream product

• 344251-65-6 t-butyl β-methyl-β-(p-ethylphenyl)glycidate 
• 937-30-4 4-ethylacetophenone 
• 105-39-5 chloroacetic acid ethyl ester 
• 4009-98-7 (methoxymethyl)triphenylphosphonium chloride 

Relevant academic research and scientific papers

An Asymmetric SN2 Dynamic Kinetic Resolution

The SN2 reaction exhibits the classic Walden inversion, indicative of the stereospecific backside attack of the nucleophile on the stereogenic center. Observation of the inversion of the stereocenter provides evidence for an SN2-type displacement. However, this maxim is contingent on substitution proceeding on a discrete stereocenter. Here we report an SN2 reaction that leads to enantioenrichment of product despite starting from a racemic mixture of starting material. The enantioconvergent reaction proceeds through a dynamic Walden cycle, involving an equilibrating mixture of enantiomers, initiated by a chiral aminocatalyst and terminated by a stereoselective SN2 reaction at a tertiary carbon to provide a quaternary carbon stereocenter. A combination of computational, kinetic, and empirical studies elucidates the multifaceted role of the chiral organocatalyst to provide a model example of the Curtin-Hammett principle. These examples challenge the notion of enantioenriched products exclusively arising from predefined stereocenters when operating through an SN2 mechanism. Based on these principles, examples are included to highlight the generality of the mechanism. We anticipate the asymmetric SN2 dynamic kinetic resolution to be used for a variety of future reactions.

Rhodium-catalyzed asymmetric hydrogenation of β-branched enamides for the synthesis of β-stereogenic amines

Using a rhodium complex of a bisphosphine ligand (R)-SDP, β-branched simple enamides with a (Z)-configuration were hydrogenated to β-stereogenic amines in quantitative yields and with excellent enantioselectivities (88-96% ee).

New aromatic rearrangement accompanying ring closure of 2-arylpropylidenemalonodinitriles to 1-aminonaphthalene-2-carbonitriles

Cyclization and a rearrangement in concentrated sulfuric acid of 2-(4-substituted-phenyl)propylidenemalonodinitriles (1) into 1-amino-4-methyl-6-substituted-naphthalene-2-carbonitriles (5) appears to involve a series of steps such as ipso electrophilic attack of the protonated nitrile function on the para position of the phenyl group, opening of a spirobenzenium cation or its transformation, and ring reclosure to the naphthalene framework with participation of the secondary alkyl carbocation as an active electrophile.

A Comparative Study of Pyrolysis and Decarboxylation of β-Substituted t-Butyl Glycidates

A series of t-butyl glycidates (Ia-i) have been prepared by Darzens condensation of carbonyl compounds with t-butyl chloroacetate in the presence of potassium t-butoxide.The pyrolysis of these esters (I) and the decarboxylation of potassium salts of the corresponding acids result in the same higher aldehydes (II) though in varying proportions.The latter procedure has, however, been found to be superiour in all the cases.Structural assignments of I and II are based on elemental analyses and spectral data (IR, PMR).Resolution of cis- and trans-isomers of I has been achieved in three cases.