89818-51-9

Upstream product

• 1823-91-2 (S)-α-phenylpropionitrile 
• 74-86-2 acetylene 
• 15260-65-8 2-(1-phenylvinyl)pyridine 
• 148493-07-6 N-methoxy-N-methyl-2-pyridinecarboxamide 
• 98-98-6 2-Picolinic acid 
• 91-02-1 phenyl(pyridin-2-yl)methanone 
• 89818-49-5 (S-)-(-) 1-phenylethyl 2-pyridyl sulfide 
• 87905-06-4 1-phenylethyl 2-pyridyl sulfoxide 

Relevant academic research and scientific papers

Phosphite mediated asymmetric N to C migration for the synthesis of chiral heterocycles from primary amines

A phosphite mediated stereoretentive C-H alkylation ofN-alkylpyridinium salts derived from chiral primary amines was achieved. The reaction proceeds through the activation of theN-alkylpyridinium salt substrate with a nucleophilic phosphite catalyst, followed by a base mediated [1,2]aza-Wittig rearrangement and subsequent catalyst dissociation for an overall N to C-2 alkyl migration. The scope and degree of stereoretention were studied, and both experimental and theoretical investigations were performed to support an unprecedentedaza-Wittig rearrangement-rearomatization sequence. A catalytic enantioselective version starting with racemic starting material and chiral phosphite catalyst was also established following our understanding of the stereoretentive process. This method provides efficient access to tertiary and quaternary stereogenic centers in pyridine systems, which are prevalent in drugs, bioactive natural products, chiral ligands, and catalysts.

Photoenzymatic Hydrogenation of Heteroaromatic Olefins Using ‘Ene’-Reductases with Photoredox Catalysts

Flavin-dependent ‘ene’-reductases (EREDs) are highly selective catalysts for the asymmetric reduction of activated alkenes. This function is, however, limited to enones, enoates, and nitroalkenes using the native hydride transfer mechanism. Here we demonstrate that EREDs can reduce vinyl pyridines when irradiated with visible light in the presence of a photoredox catalyst. Experimental evidence suggests the reaction proceeds via a radical mechanism where the vinyl pyridine is reduced to the corresponding neutral benzylic radical in solution. DFT calculations reveal this radical to be “dynamically stable”, suggesting it is sufficiently long-lived to diffuse into the enzyme active site for stereoselective hydrogen atom transfer. This reduction mechanism is distinct from the native one, highlighting the opportunity to expand the synthetic capabilities of existing enzyme platforms by exploiting new mechanistic models.

Pyridine-directed asymmetric hydrogenation of 1 1-diarylalkenes

Highly enantioselective pyridine-directed rhodium-catalyzed asymmetric hydrogenation of challenging 1 1-diarylalkenes is achieved by using [Rh(NBD)DuanPhos]BF4 as a precatalyst. Various types of 2-pyridine substituted 1 1-diarylalkenes could be hydrogenated with good to excellent enantioselectivities which provide an efficient route to the synthesis of pharmaceutically and biologically active compounds containing a 2-pyridyl ethane unit.

DiPAMP's big brother "i-Pr-SMS-Phos" exhibits exceptional features enhancing rhodium(I)-catalyzed hydrogenation of olefins

Switching Knowles DiPAMP's {DiPAMP = l,2-bis[(o-anisyl)(phenyl)phosphino] ethane} MeO groups with i-PrO ones led to the iPr-SMS-Phos {i-Pr-SMS-Phos = l,2-bis[(o-isopropoxyphenyl)(phenyl)phosphino]ethane} ligand which displayed a boosted catalyst activity coupled with an enhanced enantioselectivity in the rhodium(I)catalyzed hydrogenation of a wide-range of representative olefinic substrates (dehydro-a-amido acids, itaconates, acrylates, enamides, enol acetates, α,α-diarylethylenes, etc). The rhodium(I)-(i-PrSMS-Phos) catalytic profile was investigated revealing its structural attributes and robustness, and in contrast to the usual trend, 31P NMR analysis revealed that its methyl (Z)-α-acetamidocinnamate (MAC) adduct consisted of a reversed diastereomeric ratio of 1.4:1 in favour of the most reactive diastereomer.

OPTICALLY ACTIVE HETEROAROMATIC COMPOUNDS: X. THE SYNTHESIS OF OPTICALLY ACTIVE DISUBSTITUTED PYRIDINES: AN OVERVIEW

An extended study on the synthesis of optically disubstituted pyridines containing a single chiral substituent with at least one chirality centre adjacent to the heterocyclic ring, carried out by the authors over the past few years is reported.A special c

Ligand Coupling within ?-Sulphurane Intermediates formed in the Reaction of Benzyl 2-Pyridyl and Related Sulphoxides with Grignard reagents

The reaction of benzyl or 1-phenylethyl 2-pyridyl sulphoxide (1) or (18) with a Grignard reagent was found to give the ligand-coupling product, i.e., 2-benzylpyridine or 2-(1-phenylethyl)pyridine (2) or (22) in excellent yield.This coupling reaction was found to proceed whithin the ?-sulphurane formed as an intermediate upon treatment of benzyl 2-pyridyl and related sulphoxides with a Grignard reagent.The stereochemical course of this coupling reaction involves complete retention at the benzylic carbon.

LIGAND COUPLING THROUGH ?-SULFURANE --- COMPLETE RETENTION OF CONFIGURATION OF 1-PHENYLETHYL GROUP IN THE REACTION OF 1-PHENYLETHYL 2-PYRIDYL SULFOXIDE WITH GRIGNARD REAGENT

The reaction of benzyl or 1-phenylethyl 2-pyridyl sulfoxide with Grignard reagent proceeds via a ?-sulfurane as an intermediate to give the coupling product, 2-benzylpyridine or 2-(1-phenylethyl)pyridine in quantitative yield.Stereochemistry for this reaction is complete retention at the benzylic carbon atom.