Catalytic hydrogenation of carboxylic acid esters is essential for the green production of pharmaceuticals, fragrances, and fine chemicals. Herein, we report the efficient hydrogenation of esters with manganese catalysts based on simple bidentate aminophosphine ligands. Monoligated Mn PN complexes are particularly active for the conversion of esters into the corresponding alcohols at Mn concent...

SYNLETT 2006, No. 8, pp 1169–117215.05.2006 Advanced online publication: 10.03.2006 DOI: 10.1055/s-2006-932461; Art ID: W30605ST © Georg Thieme Verlag Stuttgart · New York Abstract: Various enantiomerically pure a-hydroxy esters were synthesized by asymmetric hydrogenation of a-keto esters catalyzed by Ru-Cn-Tunephos complex. Up to 97.1% ee has been achieved for both a-aryl and a-alkyl substitu...

Primary and secondary alcohols react with vinyl or isopropenyl acetate at room temperature in the presence of catalytic amounts (0.05-1 mol %) of Y5(OiPr)13O to give the corresponding esters. In selected cases, the yttrium catalyst promotes the selective O-acylation of amino alcohols without the formation of the amide. Enol esters also react with alpha-amino acid esters in the absence of a cata...

A resin-bound dinuclear zinc(II) complex for the selective capture of pyrophosphopeptides is reported. The metal complex binds diphosphate esters over other anionic groups, such as monophosphate esters, sulfate esters, and carboxylic acids, with high specificity. Immobilization of the compound provided a reagent capable of binding and retaining nanomolar quantities of pyrophosphopeptide in the ...

The enantiospecific conversion of chiral secondary boronic esters into alkylfluorides is reported. Boronate complexes derived from boronic esters and PhLi were used as nucleophiles, with Selectfluor II as the electrophilic fluorinating agent, to afford alkylfluorides in short reaction times. The addition of styrene as a radical trap was found to enhance enantiospecificity. A broad range of alky...

Processing of lignocellulosic biomass or organic wastes produces a plethora of chemicals such as short, linear carboxylic acids, known as carboxylates, derived from anaerobic digestion. While these carboxylates have low values and are inhibitory to microbes during fermentation, they can be biologically upgraded to high-value products. In this study, we expanded our general framework for biologi...

This thesis is concerned with the synthesis of acid labile co-polymers. Two polymer systems were examined (1) polyacetals and (2) poly(ortho esters). As for poly(ortho esters), there is a need for better synthetic methods to prepare these polymers more easily without the need of stringent anhydrous conditions, with more broad structural variation, and in a more cost effective manner. Pendent fu...

Biodiesel, defined as the monoalkyl esters of vegetable oils and animal fats, is an alternative to conventional petroleum-based diesel fuel. Biodiesel has been prepared from numerous common vegetable oils or fats as well as new or less common feedstocks. Major issues facing biodiesel include several technical aspects such as cold flow and oxidative stability as well as availability of sufficien...

l'auteur explique le comportement des esters cycliques neutres vis -a- vis de l'eau ,de l'acide chlorhydrique , ainsi que la polymerisation des ethylphosphates cycliques d'ethylene et de propylene par des traces d'eau. les produits resultant de la plymerisation de ce dernicr phosphate cyclique sont plus complexes que ceux obtenus dans les memes conditions avec 1'et...

An LC-MS method using a single quadrupole mass spectrometer was developed for direct analysis of glycidyl esters of fatty acids in vegetable oils. Without any sample clean-up, this method provided acceptable recovery of seven glycidyl esters, comparable results to a previously-published method utilizing two solid-phase extraction steps, and consistent detection parameters after greater than 200...