82950-72-9Relevant articles and documents
A Proline Mimetic for the Design of New Stable Secondary Structures: Solvent-Dependent Amide Bond Isomerization of (S)-Indoline-2-carboxylic Acid Derivatives
Pollastrini, Matteo,Lipparini, Filippo,Pasquinelli, Luca,Balzano, Federica,Barretta, Gloria Uccello,Pescitelli, Gennaro,Angelici, Gaetano
, p. 7946 - 7954 (2021/06/28)
A thorough experimental and computational study on the conformational properties of (S)-indoline-2-carboxylic acid derivatives has been conducted. Methyl (S)-1-acetylindoline-2-carboxylate, both a mimetic of proline and phenylalanine, shows a remarkable tendency toward the cis amide isomer when dissolved in polar solvents. This behavior is opposite to the general preference of proline for the trans isomer, making indoline-2-carboxylic acid a good candidate for the design of different secondary structures and new materials.
Asymmetric hydrogenation of 2-substituted N-protected-indoles catalyzed by rhodium complexes of BINOL-derived phosphoramidites
Mrsic, Natasa,Jerphagnon, Thomas,Minnaard, Adriaan J.,Feringa, Ben L.,de Vries, Johannes G.
experimental part, p. 7 - 10 (2010/04/06)
The rhodium-catalyzed asymmetric hydrogenation of 2-substituted N-protected-indoles using monodentate phosphoramidites as ligands was examined. Full conversion and 74% ee, were obtained with a catalyst based on PipPhos. The use of a catalytic amount of base is necessary for activity; best results were obtained with Cs2CO3.
NEW PROCESSES FOR THE PREPARATION OF OPTICALLY PURE INDOLINE-2-CARBOXYLIC ACID AND N-ACETYL-INDOLINE-2-CARBOXYLIC ACID
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Page/Page column 17, (2008/06/13)
Processes for: a) separating the enantiomers of indoline-2-carboxylic acid of formula (I): comprising of: (i) combining the (R, S) indoline-2-carboxylic acid with (1S)- or (1R)-10- camphorsulfonic acid as the resolving agent in a resolution solvent and crystallizing from the said mixture the diastereomeric salt of (S)- or (R)-indoline-2-carboxylic acid with optically pure (1S)- or (1R)-10-camphorsulfonic acid; (ii) regenerating the (S)- or (R)-indoline-2-carboxylic acid from the crystallized diastereomeric salt by using a suitable base or basic ion-exchange resin; and b) for the optical resolution of N-acetyl-indoline-2-carboxylic acid of formula, (II): comprising of: (i) combining the (R, S)-N-acetyl-indoline-2-carboxylic acid with (S)- or (R)- phenylglycinol as the resolving agent in a resolution solvent and crystallizing from the said mixture the diastereomeric salt of (S)- or (R)-N-acetyl-indoline-2-carboxylic acid with optically pure phenylglycinol; (ii) regenerating the (S)- or (R)-N-acetyl-indoline-2-carboxylic acid from the crystallized salt by using a suitable acid or acidic ion-exchange resin. The non-selected enantiomer may then be racemized and the process (a) or (b) repeated thus to obtain substantial conversion of the material to one enantiomer.