615-81-6Relevant articles and documents
PROCESSES FOR THE PREPARATION OF ALPHA-HYDROXY ESTERS VIA GRIGNARD COUPLING AND THIOLATION REACTIONS
-
Paragraph 0098-0100, (2021/05/29)
The present disclosure provides processes for preparing an alpha-hydroxy ester by addition of a vinyl Grignard reagent to an oxalate ester and thiolation of the resulting double bond. Also provided are alpha-hydroxy esters and synthetic intermediates prepared according to processes disclosed herein and compositions comprising the alpha-hydroxy esters.
Cationic Chiral Pd-Catalyzed “Acetylenic” Diels–Alder Reaction: Computational Analysis of Reversal in Enantioselectivity
Honda, Kazuya,Ohkura, Shun,Hayashi, Yoshihiro,Kawauchi, Susumu,Mikami, Koichi
supporting information, p. 2842 - 2846 (2018/09/25)
The highly enantioselective Diels–Alder reaction of acetylenic dienophiles is shown to be effectively catalyzed by cationic chiral palladium complexes. Not only the degree but also the sense of enantioselectivity critically depends on the steric demand of ligands. Computational analyses indicate that the steric demand does not affect the endo/exo-selectivity but the enantioface selectivity of dienes.
Palladium catalyzed oxidative carbonylation of alcohols: Effects of diphosphine ligands
Amadio, Emanuele,Freixa, Zoraida,Van Leeuwen, Piet W. N. M.,Toniolo, Luigi
, p. 2856 - 2864 (2015/07/14)
The catalytic activity of a series of palladium diphosphine complexes of the type [PdX2(P∩P)] has been studied in the oxidative carbonylation of i-PrOH with p-benzoquinone as an oxidant. Diphosphine ligands have been chosen in order to cover a wide range of bite angles and electronic and steric parameters. Their properties have been correlated with the catalytic activity and selectivity of the reaction. The best catalytic performance has been achieved with weakly coordinating anions as well as non-bulky and electron-donating P∩P ligands with a relatively wide bite angle yet capable of maintaining a cis-coordination, such as cis-[Pd(OTs)2(pMeO-dppf)]. These results and those on the reactivity of dicarboalkoxy species of the type cis-[Pd(COOMe)2(P∩P)] toward reductive elimination, which is a crucial step in oxalate formation, suggest that the slow step of the catalysis depends on the nature of the P∩P ligand.