800402-10-2Relevant academic research and scientific papers
Access to enantioenriched α-amino esters via rhodium-catalyzed 1,4-addition/enantioselective protonation
Navarre, Laure,Martinez, Remi,Genet, Jean-Pierre,Darses, Sylvain
, p. 6159 - 6169 (2008/12/20)
Conjugate addition of potassium trifluoro(organo)borates 2 to dehydroalanine derivatives 1, mediated by a chiral rhodium catalyst and in situ enantioselective protonation, afforded straightforward access to a variety of protected α-amino esters 3 with high yields and enantiomeric excesses up to 95%. Among the tested chiral ligands and proton sources, Binap, in combination with guaiacol (2-methoxyphenol), an inexpensive and nontoxic phenol, afforded the highest asymmetric inductions. Organostannanes have also shown to participate in this reaction. By a fine-tuning of the ester moiety, and using Difluorophos as chiral ligand, increased levels of enantioselectivity, generally close to 95%, were achieved. Deuterium labeling experiments revealed, and DFT calculation supported, an unusual mechanism involving a hydride transfer from the amido substituent to the α carbon explaining the high levels of enantioselectivity attained in controlling this α chiral center.
PYRROLOPYRIDINE-2-CARBOXYLIC ACID AMIDE INHIBITORS OF GLYCOGEN PHOSHORYLASE
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Page 73-74, (2008/06/13)
Compounds represented by Formula (I): or pharmaceutically acceptable salts thereof, are inhibitors of glycogen phosphorylase and are useful in the prophylactic or therapeutic treatment of diabetes, hyperglycemia, hypercholesterolemia, hyperinsulinemia, hyperlipidemia, hypertension, atherosclerosis or tissue ischemia e.g. myocardial ischemia, and as cardioprotectants.
