180605-35-0Relevant academic research and scientific papers
Guanidinium Ylide mediated aziridination from arylaldehydes: Scope and limitations in the formation of unactivated 3-arylaziridine-2-carboxylates
Oda, Yukiko,Hada, Kihito,Miyata, Marie,Takahata, Chisato,Hayashi, Yukiko,Takahashi, Masato,Yajima, Naoki,Fujinami, Makiko,Ishikawa, Tsutomu
, p. 2201 - 2219 (2014/08/18)
The scope and limitations of guanidinium ylide mediated aziridinations from arylaldehydes yielding unactivated 3-arylaziridine-2-carboxylates, applicable to asymmetric synthesis, are discussed. Georg Thieme Verlag Stuttgart. New York.
Kinetic resolution of racemic carboxylic acids by an L-histidine-derived sulfonamide-induced enantioselective esterification reaction
Ishihara, Kazuaki,Kosugi, Yuji,Umemura, Shuhei,Sakakura, Akira
supporting information; experimental part, p. 3191 - 3194 (2009/05/27)
(Chemical Equation Presented) The direct and catalytic kinetic resolution of racemic carboxylic acids bearing a Bronsted base such as O-protected α-hydroxy carboxylic acids and N-protected α-amino acids has been accomplished through an L-histidine-derived sulfonamide-induced enantioselective esterification reaction with tert-butyl alcohol for the first time. Highly asymmetric induction [S(kfast/kslow) = up to 56] has been achieved under the equilibrium between a chiral catalyst and two diastereomeric acylammonium salts through an intramolecular hydrogen-bonding interaction.
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.
