524696-63-7Relevant academic research and scientific papers
Synthesis of α,α-disubstiuted unnatural amino acid derivatives using the aza-[2,3]-Wittig sigmatropic rearrangement
Anderson, James C.,Skerratt, Sarah
, p. 2871 - 2879 (2002)
Aza-[2,3]-Wittig rearrangement precursors derived from alanine, valine, phenylalanine and phenylglycine were synthesised with diethylamide and methylester anion stabilising groups. In the amide series only- the alanine derived precursor rearranged upon deprotonation with KH. In the ester series the alanine, valine and phenylalanine precursors rearranged successfully with KH. The phenylalanine ester precursor gave an unselective rearrangement whereas rearrangement of the alanine and valine ester precursors gave levels and sense of diastereoselectivity in line with our transition state model. The products are chiral α,αdisubstituted-α-amino acid derivatives possessing two adjacent stereocentres and a vinyl silane synthetic handle.
Three-Component Reactions to Spirocyclic Pyrrolidinonylformimidamides: α-Isocyano Lactams as Two-Atom Unit in Silver-Catalyzed Formal [3 + 2] Cycloaddition Reactions
George, Jimil,Kim, Seong-Yoon,Oh, Kyungsoo
, p. 7192 - 7196 (2018)
A facile approach to spirocyclic pyrrolidinonylformimidamides has been developed via three-component reactions of isocyanides, alkenes, and amines. The reaction proceeds through a sequence of two distinct reaction pathways; the base-catalyzed conjugate addition of α-isocyano lactams to electron-deficient alkenes and the Ag(I)-catalyzed amine insertion to the isocyanide moiety. Both reactions display markedly different reaction kinetics, allowing the one-pot three-component reactions to be performed in the presence of respective catalysts, a Br?nsted base and a silver salt. The formation of spirocyclic pyrrolidin-2-ones represents an unusual use of α-isocyano lactam as a two-atom unit in a formal [3 + 2] cycloaddition reaction. The successful identification of ways to defy the typical three-atom unit role of α-isocyano carbonyl compounds in the [3 + 2] cycloaddition pathways manifests a rapid assembly of medicinally important spirocyclic scaffolds from readily available starting materials.
Enantiomeric resolution of α-amino acid derivatives on two diastereomeric chiral stationary phases based on chiral crown ethers incorporating two different chiral units
Kim, Hee Jin,Choi, Hee Jung,Cho, Yoon Jae,Hyun, Myung Ho
body text, p. 1551 - 1554 (2010/10/20)
Two diastereomeric chiral stationary phases (CSPs) were applied to the liquid chromatographic resolution of various racemic a-amino methyl esters, α-amino N,N-diethylamides and α-amino N-propylamides. The CSP incorporating (R)-3,3' -diphenyl-1,1' -binaphtyl and (R,R)-tartaric acid unit as chiral barriers did not show any chiral recognition. In contrast, the CSP incorporating (R)-3,3'-diphenyl-1,1'-binaphtyl and (S,S)-tartaric acid unit as chiral barriers was found to show excellent chiral recognition especially for the two enantiomers of a-amino N-propylamides. Some of a-amino methyl esters and α-amino N,N-diethylamides were also resolved on the CSP incorporating (R)-3,3'-diphenyl-1,1'-binaphtyl and (S,S)-tartaric acid unit. From these results it was concluded that the two chiral units composing the diastereomeric CSPs can show "matched" or "mismatched" effect on the chiral recognition according to their absolute stereochemistry.
