71776-82-4

Upstream product

• 42307-58-4 3-phenylbutanal 
• 75-36-5 acetyl chloride 
• 84999-94-0 (R)-(-)-cinnamyl 2-methoxy-2-phenylpropyl ether 
• 84999-95-1 (2R)-2-methoxy-2-phenylpropyl (Z)-3-phenyl-1-butenyl ether 
• 20883-16-3 1-acetoxy-3-phenylbut-2-ene 
• 108-24-7 acetic anhydride 
• 16251-77-7 (3S)-3-phenylbutanal 
• 110-05-4 di-tert-butyl peroxide 
• 122-72-5 3-phenylpropyl acetate 
• 591-87-7 Allyl acetate 
• 2722-36-3 3-phenyl-1-butanol 
• 934-10-1 3-phenylbut-1-ene 
• 100-42-5 styrene 
• 20883-16-3 β-methylcinnamyl acetate 

Downstream Products

• 2031-46-1 (R)-3-phenylbutanol 
• 2031-46-1 (3S)-3-phenylbutan-1-ol 

Relevant academic research and scientific papers

C(sp3)-H methylation enabled by peroxide photosensitization and Ni-mediated radical coupling

The “magic methyl” effect describes the change in potency, selectivity, and/or metabolic stability of a drug candidate associated with addition of a single methyl group. We report a synthetic method that enables direct methylation of C(sp3)-H bonds in diverse drug-like molecules and pharmaceutical building blocks. Visible light-initiated triplet energy transfer promotes homolysis of the O-O bond in di-tert-butyl or dicumyl peroxide under mild conditions. The resulting alkoxyl radicals undergo divergent reactivity, either hydrogen-atom transfer from a substrate C-H bond or generation of a methyl radical via b-methyl scission. The relative rates of these steps may be tuned by varying the reaction conditions or peroxide substituents to optimize the yield of methylated product arising from nickel-mediated cross-coupling of substrate and methyl radicals.

Iridium catalysts with Chiral bicyclic pyridine-phosphane ligands for the asymmetric hydrogenation of olefins

New bicyclic pyridine-phosphane ligands were prepared, and their iridium complexes were evaluated in asymmetric hydrogenation of trisubstituted olefins with non-coordinating and weakly coordinating substituents. The iridium catalysts showed high reactivity and enantioselectivity for both types of olefins. New pyridine-derived N,P-chelated iridium catalysts were prepared and evaluated in the asymmetric hydrogenation of trisubstituted olefins. High conversions and enantioselectivities were obtained. Copyright

Solvent-free transesterification in a ball-mill over alumina surface

An efficient procedure for transesterification has been developed in a ball-mill in the absence of any solvent, acid/base or metal catalyst. A variety of methyl, ethyl, allyl esters have been transesterified to higher benzyl and other esters in high yields by this procedure.

Iridium catalysts with chiral imidazole-phosphine ligands for asymmetric hydrogenation of vinyl fluorides and other olefins

New chiral bidentate imidazole-phosphine ligands have been prepared and evaluated for the iridium-catalysed asymmetric hydrogenation of olefins. The imidazole-phosphine-ligated iridium catalysts hydrogenated trisubstituted olefins with the same sense of enantiodiscrimination as known iridium catalysts possessing oxazole and thiazole as N-donors. The imidazole-based catalysts were shown to hydrogenate vinyl fluorides, in some cases with the highest ee values published to date.

Asymmetric hydrogenation of tri-substituted alkenes with Ir-NHC-thiazole complexes

An efficient chiral N-heterocyclic carbene ligand for the Ir-catalyzed asymmetric hydrogenation of largely unfunctionalized tri-substituted olefins has been developed. The Ir-NHC-thiazole catalyst is able to reduce a large variety of substrates with excellent conversions and good enantioselectivities with ee's ranging from 34% to 90%, depending on the geometry around the double bond of the substrates.

Heterodimerization of Olefins. 1. Hydrovinylation Reactions of Olefins That Are Amenable to Asymmetric Catalysis

Through a systematic examination of ligand and counterion effects, new protocols for a nearly quantitative and highly selective codimerization of ethylene and various functionalized vinylarenes have been discovered. In a typical reaction, 4-bromostyrene and ethylene undergo codimerization in the presence of 0.0035 equiv each of [(allyl)NiBr]2, triphenylphosphine, and AgOTf in CH2Cl2 at -56 °C to give 3-(4-bromophenyl) -1-butene in >98% yield and selectivity. Corresponding reactions with [(allyl)PdX]2 are much less efficient and less selective and may require further optimization before a viable system can be identified. Another useful protocol that gives comparable yield and selectivity involves the use of a single-component catalyst prepared from allyl 2-diphenylphosphinobenzoate, Ni(COD)2, and (C6F5)3B. Recognition of a synergistic relationship between a chiral hemilabile ligand (for example, (R)-2-methoxy-2′-diphenylphosphino-1,1′-binaphthyl, MOP) and a highly dissociated counteranion (BARF or SbF6) in an enantioselective version of the Ni-catalyzed reaction raises the prospects of developing a practical route for the synthesis of 3-arylbutenes. Several pharmaceutically relevant compounds, including widely used 2-arylpropionic acids, can be synthesized from these key intermediates. This reaction appears to be quite general. Synthesis of several new 2-diphenylphosphino-1,1-binaphthyl derivatives, prepared to probe the effect of hemilabile coordination on the efficiency and selectivity of the reaction, are also described.

A NEW AND EFFECTIVE ASYMMETRIC SYNTHESIS OF 3-PHENYLALKANALS

Highly optically active 3-phenylalkanals were obtained by the reaction of alkyl halides and a chiral homoenolate equivalent derived from the cinnamyl ether 3 and potassium diisopropylamide, followed by acidic hydrolysis.

CHIRAL HOMOENOLATE EQUIVALENTS. I. ASYMMETRIC SYNTHESIS OF β-SUBSTITUTED ALDEHIDES VIA METALATED CHIRAL ALLYLAMINES

Metalated chiral allylamines of type 2 (M = Li, K) are used as chiral homoenolate equivalents and allow after alkylation and acidic hydrolysis asymmetric C-C bond formations to β-substituted aldehydes in enantiomeric excesses up to 67percent.