615576-88-0Relevant articles and documents
Synthesis of trifluoromethyl substituted nucleophilic glycine equivalents and the investigation of their potential for the preparation of α-amino acids
Bergagnini-Kolev, Mackenzie,Howe, Mitchell,Burgess, Emily,Wright, Payton,Hamburger, Samantha,Zhong, Zhennan,Ellis, Shawna B.,Ellis, Trevor K.
, (2021)
The synthetic preparation of several Ni(II) complexed Schiff Bases of glycine will be introduced, as well as investigations into their reactivity and utility. Key to these investigations is the incorporation of electron-withdrawing trifluoromethyl groups within the framework of the conjugated system that stabilizes the enolate derived from the glycine component. Reactivity was evaluated for each of the complexes under phase transfer catalyzed alkylations with hydroxide bases, as well as the DBU catalyzed Michael Additions of optically active 3′-substituted-2-oxazoladinone amides of unsaturated carboxylic acids. It was found that the trifluoromethyl containing nucleophilic glycine equivalents were more reactive than their non-trifluoromethyl analogues in both reaction types. Therefore, the application of these modified Ni(II) complexes of glycine Schiff Bases are useful for the preparation of α-amino acids through phase transfer catalyzed alkylation as well as the preparation of optically pure β-substituted pyroglutamic acid precursors.
Design, synthesis, and evaluation of a new generation of modular nucleophilic glycine equivalents for the efficient synthesis of sterically constrained α-amino acids
Ellis, Trevor K.,Ueki, Hisanori,Yamada, Takeshi,Ohfune, Yasufumi,Soloshonok, Vadim A.
, p. 8572 - 8578 (2007/10/03)
A new generation of modular achiral glycine equivalents have been evaluated with respect to their synthetic utility for the production of tailor-made, sterically constrained α-amino acids, which proved to be the most efficient approach developed to date for the synthesis of symmetrical α,α-disubstituted-α-amino acids. Among the new series of achiral glycine equivalents, one was found to be a superior glycine derivative for the Michael additions with various (R)- or (S)-N-(E-enoyl)-4-phenyl-1,3- oxazolidin-2-ones representing a general and practical synthesis of sterically constrained β-substituted pyroglutamic acids. In particular, the application of these complexes allowed for the preparation of several β-substituted pyroglutamic acids which include electron-releasing and sterically demanding substituents in the structure thus increasing the synthetic efficiency and expanding the generality of these Michael addition reactions.
Highly diastereoselective synthesis of new, carbostyril-based type of conformationally-constrained β-phenylserines
Ueki, Hisanori,Ellis, Trevor K.,Khan, Masood A.,Soloshonok, Vadim A.
, p. 7301 - 7306 (2007/10/03)
We have demonstrated that the readily available amido-keto compounds 5, with prearranged carbonyl and glycine moieties, under strongly basic conditions easily undergo complete and highly diastereoselective cyclization, affording a generalized and practical access to the conformationally constrained phenylserine derivatives 4. High chemical yields, virtually complete diastereoselectivity combined with the operational convenience of the experimental procedures render this method useful for preparation of these diastereomerically pure derivatives.
