26976-78-3Relevant academic research and scientific papers
A Cooperative Strategy for the Highly Selective Intermolecular Oxycarbonylation Reaction of Alkenes using a Palladium Catalyst
Li, Ming,Yu, Feng,Qi, Xiaoxu,Chen, Pinhong,Liu, Guosheng
supporting information, p. 13843 - 13848 (2016/10/26)
A novel method for intermolecular functionalization of terminal and internal alkenes has been designed. The electrophilic reagent, hypervalent iodine, plays a key role in this process by activating the alkene C=C bond for nucleophilic addition of the palladium catalyst. This process generates an iodonium-containing palladium species which undergoes CO insertion. The new approach, intermolecular oxycarbonylaton reactions of alkenes, has been achieved and carried out under mild reaction conditions to produce the corresponding β-oxycarbonylic acids with excellent efficiencies and levels of regio- and diastereoselectivity.
β-substituted β-phenylpropionyl chymotrypsins. Structural and stereochemical features in stable acyl enzymes
Reed,Katzenellenbogen
, p. 1162 - 1176 (2007/10/02)
In order to develop effective alternate substrate inhibitors for serine proteases, we have prepared a series of β-substituted β-phenylpropionic acid esters related to some systems known to form stable acyl enzymes with α-chymotrypsin. Some of these compounds were prepared in enantiomerically pure form by asymmetric synthesis. Acyl enzyme species were generated from chymotrypsin by reaction with the active esters, and the progress of deacylation was monitored by the proflavin displacement assay. In some cases, it was possible to distinguish two different deacylation rates that correspond to the two enantiomers. β-Phenylpropionic acyl enzymes with β-substituents that are nonpolar were not especially stable, but a number of the polar derivatives and particularly the acylamino derivatives showed slow rates of deacylation (k(d) less than 0.005 min-1), with three systems showing deacylation enantioselectivities in the range of 500-1500. These results are consistent with a model in which additional stabilization of the acyl enzyme and enantioselectivity in the deacylation process derives from an additional hydrogen bond between the acyl enzyme species (as an acceptor) and the enzyme (as a donor). A number of active site residues that might be involved in this hydrogen bond are discussed.
STUDIES ON PIG LIVER ESTERASE-MEDIATED HYDROLYSES OF 3-HYDROXY ESTERS
Santaniello, Enzo,Ferraboschi, Patrizia,Grisenti, Paride,Manzocchi, Ada,Trave, Susanna
, p. 581 - 584 (2007/10/02)
At 25 deg C, the pig liver esterase (PLE)-catalyzed hydrolyses of 3-hydroxy esters 2 and 3 proceed in aqueous phosphate buffer with moderate enantioselectivity, which can be increased by carrying out the reaction in an aqueous medium containing 20percent
