Asymmetric Synthesis of Indoline–Benzodiazepine Scaffold Catalyzed by Chiral Imidodiphosphoric Acids

Abstract

Chiral indoline-benzodiazepines were synthesized via an enantioselective Pictet-Spengler-typer eaction catalyzed by chiral imidodiphosphoric acids. Av arietyo f substitution patterns were achieved at room temperature by using 5mol %c atalysts with high yields (up to 97 %) and enantioselectivities (up to 99 % ee).

Organocatalyzed Asymmetric Pictet‐Spengler Reactions

“…However diminished yield and steroselectivities were obtained with electron‐rich aldehydes which went up to excellent levels with strongly deactivated aldehydes(Scheme 67b) [68c] . Inthe same year i. e. 2017, another variant of the reaction was disclosedinvolving 2‐ (1H‐ indoline) anilines 258 or N ‐aryl substituted 7‐amino indoline derivatives 259 and β‐ naphthyl pyruvate 148 a in the presence of H8‐BINOL derived imidodiphosphoric acid yielding optically active indoline‐benzodiazepine frameworks 260 / 261 (Scheme 67c) [68d] …”

Accessing unnatural α-amino acids with tetrasubstituted stereogenic centersviacatalytic enantioselective reactions of ketimine-type α-iminoesters/α-iminoamides

“…, 198b and 198c ) in enantioselective Pictet–Spengler-type reaction involving 2-(1 H -indoline)anilines or 1-aryl-7-aminoindolines during the synthesis of seven-membered heterocycles 199 and 200 (Scheme 82, middle and bottom). 135…”

Binaphthyl-derived armchair-type molecular carbon rings with chirality: synthesis and optical properties

“…Among various chiral molecules, 1,1′-bi-2-naphthol (BINOL) exhibits unique features, including a stable chiral configuration, multiple functional positions, and commercial availability. 27 To date, BINOL has been extensively investigated in molecular recognition, 28 fluorescence sensors, 29 asymmetric synthesis, 30 and chiral materials. 31 Taking its advantages over other candidates into account, we chose BINOL as the starting material to build foreign chiral units.…”