The four-step straightforward synthesis of enantiopure (+)- and (-)-2,2',5,5'-tetramethyl-4,4'-bis-(diphenylphoshino)-3,3'-bithiophene (tetraMe-BITIOP), a new C2-symmetry chelating ligand for transition metals, is described, starting from 2,5-dimethylthiophene. complexes this electron-rich diphosphine with Ru(II) Rh(I) were used as catalysts in some homogeneous hydrogenation reactions prostereogenic carbonyl functions alpha- beta-ketoesters, carbon-carbon double bonds substituted acrylic...

An efficient and short enantioselective synthesis of (S)- (R)-tolterodine was performed by asymmetric hydrogenation a coumarin intermediate, easily obtained Heck reaction from inexpensive commercially available starting materials.

Sitagliptin, an important anti-diabetic drug, can be obtained using transaminase (TA) enzymes, which are known to promising biocatalysts for the production of highly enantiopure amines under mild reaction conditions. In industrial context, use immobilized enzymes provide several advantages, such as improved stability biocatalyst and easy product recovery. this study, a new commercially available enzyme produce sitagliptin was on inorganic organic supports two different approaches: adsorption...

Racemic (±)-3,3'-bis(diphenylphosphinyl)-1,1'-dimethyl-2,2'-biindole (1c) (N-Me-2-BINPO) and (±)-3,3'-bis(diphenylphosphinyl)-1,1'-bis(methoxymethyl)-2,2'-biindole (1d) (N-MOM-2-BINPO) were synthesized in satisfactory yields following a three-step reaction sequence, starting from indole. Resolution of racemic 1c 1d was achieved through fractional crystallization their diastereomeric adducts with optically active dibenzoyl tartaric acids, followed by alkaline decomplexation the...

Tolterodine, an important urological drug, can be conveniently prepared starting from 1-[2-hydroxy-5-methyl)phenyl]-1-phenylethylene, accessible in high yield by alumina-promoted ortho alkenylation of p-cresol with phenylacetylene. The hydroformylation this olefin, catalyzed rhodium complexes both homogeneous or aqueous biphasic system, affords the desired linear aldehyde about 80−90% yield. reductive amination aldehyde, presence HN(iPr)2 and Pd/C (5%) as catalytic precursor at 4 atm H2 48...

Hydrodechlorination reaction of 3-(benzo-1,3-dioxol-5-yl)-3-chloro-2-methylacrylaldehyde in the presence different low metal content heterogeneous mono- or bi-metallic catalysts was tested for synthesis fragrance Helional® (3-[3,4-methylendioxyphenyl]-2-methyl-propionaldehyde). In particular, mono Pd/Al2O3, Rh/Al2O3 Pd-Cu/Al2O3, Rh-Cu/Al2O3 were conditions from which it emerged that mono-Rh/Al2O3 best performing catalyst allowing to achieve 100% substrate conversion and 99% selectivity...

The use of immobilized alcohol dehydrogenases (ADHs) offers numerous advantages, especially in the reaction conditions required by industrial applications. Looking for more efficient and cost-effective methods ADH immobilization, this study we explored silica-based supports as an alternative to functionalized polymeric resins. Three commercially available ADHs were adsorption covalent bond formation. obtained supported biocatalysts applied bioreduction acetophenone some derivatives with good...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAlkylation of aromatic compounds with optically active lactic acid derivatives: synthesis pure 2-arylpropionic and estersOreste Piccolo, Franca Spreafico, Giuseppina Visentin, Ermanno ValotiCite this: J. Org. Chem. 1985, 50, 20, 3945–3946Publication Date (Print):October 1, 1985Publication History Published online1 May 2002Published inissue 1 October...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereochemical aspects of the nickel-catalyzed alkylation allylic alcoholsGiambattista Consiglio, Franco Morandini, and Oreste PiccoloCite this: J. Am. Chem. Soc. 1981, 103, 7, 1846–1847Publication Date (Print):April 1, 1981Publication History Published online1 May 2002Published inissue 1 April 1981https://doi.org/10.1021/ja00397a048RIGHTS & PERMISSIONSArticle Views545Altmetric-Citations41LEARN ABOUT THESE METRICSArticle Views are COUNTER-compliant...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTZinc salt catalyzed rearrangement of acetals optically active aryl 1-chloroethyl ketones: synthesis 2-arylpropionic acids and estersOreste Piccolo, Franca Spreafico, Giuseppina Visentin, Ermanno ValotiCite this: J. Org. Chem. 1987, 52, 1, 10–14Publication Date (Print):January 1987Publication History Published online1 May 2002Published inissue 1 January...

The asymmetric allylation of Grignard reagents by allyl phenyl ethers in the presence [(–)-(S,S)-2,3-bis (diphenylphosphino) butane](II) chloride gives rise to optically active olefins, with fair high optical yields; induction synthesis 3-ethylcyclohex-1-ene exceeds 97%.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereospecific Friedel-Crafts alkylation of aromatic compounds: synthesis optically active 2- and 3-arylalkanoic estersOreste Piccolo, Ugo Azzena, Giovanni Melloni, Giovanna Delogu, Ermanno ValotiCite this: J. Org. Chem. 1991, 56, 1, 183–187Publication Date (Print):January 1991Publication History Published online1 May 2002Published inissue 1 January...

Abstract [(−) ( R )‐1,2‐bis (Diphenylphosphino)‐1‐phenylethane]nickel (II) chloride was found to catalyze the asymmetric alkylation of some chiral and achiral allylic alcohols with Grignard reagents, leading formation optically active olefins. Enantiomer discrimination substrate takes place in alcohols.

Chiral N-heterocyclic molecules and in particular compounds with an amino functional group such as 3-aminopiperidine are valuable intermediates for the production of a large number bioactive pharmacological properties. In this paper, synthesis both enantiomers 3-amino-1-Boc-piperidine by amination prochiral precursor 1-Boc-3-piperidone using immobilized ω-transaminases (TAs-IMB), isopropylamine amine donor pyridoxal-5'-phosphate (PLP) cofactor is described. Compared to other methods, present...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExperimental evidence for the existence of catalytic sites with different steric structures in supported Ziegler-Natta catalystsPiero Pino, Giovanni Fochi, Oreste Piccolo, and Umberto GianniniCite this: J. Am. Chem. Soc. 1982, 104, 25, 7381–7383Publication Date (Print):December 1, 1982Publication History Published online1 May 2002Published inissue 1 December...