Navarre, Laure published the artcileAccess to enantioenriched α-amino esters via rhodium-catalyzed 1,4-addition/enantioselective protonation, COA of Formula: C38H24F4O4P2, the publication is Journal of the American Chemical Society (2008), 130(19), 6159-6169, database is CAplus and MEDLINE.
Conjugate addition of potassium trifluoro(organo)borates to dehydroalanine derivatives, mediated by a chiral rhodium catalyst and in situ enantioselective protonation, afforded straightforward access to a variety of protected α-amino esters 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 asym. 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.
Journal of the American Chemical Society published new progress about 503538-69-0. 503538-69-0 belongs to dioxole, auxiliary class (Atropisomeric Bisphosphine Ligands, name is (R)-5,5′-Bis(diphenylphosphino)-2,2,2′,2′-tetrafluoro-4,4′-bi-1,3-benzodioxole, and the molecular formula is C38H24F4O4P2, COA of Formula: C38H24F4O4P2.
Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem