53172-85-3

Upstream product

• 4383-18-0 2-phenyl-pentan-2-ol 
• 6228-47-3 n-propyltriphenylphosphonium bromide 
• 98-86-2 acetophenone 
• 24401-39-6 2-methyl-2-phenyl-pentenal 
• 34713-70-7 2-Phenylpropanal 
• 29443-43-4 propionaldehyde hydrazone 
• 5676-32-4 α-n-propylstyrene 
• 33215-90-6 isopropyl-(2-phenyl-propylidene)-amine 

Downstream Products

• 59231-18-4 (2R,3R)-2-Methyl-2-phenyl-3-vinyl-oxirane 

Relevant academic research and scientific papers

Highly Stereoselective Positional Isomerization of Styrenes via Acid-Catalyzed Carbocation Mechanism

The first transition metal-free highly stereoselective positional isomerization of various α-alkyl styrenes through a carbocation mechanism triggered strategy is developed by using Al(OTf)3 as a hidden Br?nsted acid catalyst, which provides facile access to value-added acyclic tri- and tetra-substituted alkenes in good yields with high stereoselectivity under mild conditions. The practicality of this protocol is further highlighted by the gram-scale synthesis, high stereoselectivity, good functional group tolerance, and simple operation. Mechanistic studies support that Al(OTf)3 acts as a hidden Br?nsted acid catalyst and a carbocation intermediate is formed.

Ruthenium(II)-catalyzed olefination: Via carbonyl reductive cross-coupling

Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(ii) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an intermolecular or intramolecular fashion. Moreover, this chemistry accommodates a variety of substrates, proceeds under mild reaction conditions with good functional group tolerance, and generates stoichiometric benign byproducts. Importantly, the coexistence of KOtBu and bidentate phosphine dmpe is vital to this transformation.

Bimolecular Formation of Radicals by H-Transfer, 7. - Bimolecular Formation of Radicals via H-Transfer with Catalysis by 7H-Benzanthracene

The transfer hydrogenation of α-methylstyrene (2) by 9,10-dihydroanthracene (1) (DHA) with 7H-benzanthracene (8) as a catalyst proceeds already at 210-260 deg C.Isotopic labeling, ESR spectroscopy, radical clock experiments, solvents effects, and thermochemical calculations support the postulated stepwise radical mechanism induced by bimolecular formation of radicals. - Key Words: Molecule-induced radical formation, kinetics of / Catalysis / ESR spectroscopy / Radical clock / Isokinetic relationship

CATALYTIC DECARBONYLATION, HYDROACYLATION, AND RESOLUTION OF RACEMIC PENT-4-ENALS USING CHIRAL BIS(DITERTIARY-PHOSPHINE) COMPLEXES OF RHODIUM(I)

Attempts to decarbonylate racemic aldehydes catalytically using rhodium(I) complexes containing chiral di-tertiary-phosphine ligands are described.Incorporation of an alkenic moiety into the aldehyde, for subsequent probing of induced asymmetry by chiral shift reagents, leads instead to formation of optically active hydroacylated products via kinetic resolution of the precursor racemic aldehyde.For example, (RS)-2-methyl-2-phenylpent-4-enal (1a) yields, on treatment with Cl, 2-methyl-2-phenylcyclopentanone with up to 69percent e.e of the (-)-(S) optical isomer and remaining unreacted aldehyde which is possibly the enantiomerically pure (-)-(R) form.Extension of this cyclization reaction to a 3,3-disubstituted pent-4-enal similarly provides a synthesis for an optically active 3,3-disubstituted cyclopentanone.Decarbonylation by-products are also observed; those from 1a appear as E- and Z-2-phenylpent-2-ene.The cyclization of 1a is catalyzed also by Rh(chiraphos)(solvent)2+ but with lower e.e.

Selective Condensation of titanium Reagent with Carbonyl Compounds

titanium reagent generated easily from allyl ethyl sulfides condensed with aldehydes to give erythro-β-hydroxy sulfides in highly regio- and stereoselective manner.In contrast, crotyl ethyl sulfide reacted with aldehydes affording δ-hydroxy vinyl sulfide exclusively.The substitution pattern of the starting sulfide can have a pronounced effect on the selectivity in this condensation reaction, erythro-β-Hydroxy sulfide obtained was transfromed stereoselectively to the trans-vinyloxirane or 1,3-alkadiene.

The Asymmetric Cyclisation of Substituted Pent-4-enals by a Chiral Rhodium Phosphine Catalyst

Treatment of the racemic disubstituted pent-4-enals (1) and (2) at ca. 150 deg C with the chiral complex Cl results in a cyclisation reaction and catalytic asymmetric synthesis of the 2,2- and 3,3-disubstituted cyclopentanones (3) and (4), respectively.