Highly Enantioselective Synthesis of 2,3-Dihydroquinazolinones through Intramolecular Amidation of Imines

Abstract

Enantioselective synthesis of 2,3-dihydroquinazolinones (DHQZs) was accomplished using readily available Sc(III)-inda-pybox as the catalyst. This is the first report on the metal catalyzed asymmetric intramolecular amidation of imines to synthesize DHQZs.

Common Pharmacophore of Structurally Distinct Small-Molecule Inhibitors of Intracellular Retrograde Trafficking of Ribosome Inactivating Proteins

“…Although asymmetric syntheses89101112 have been reported for substituted 2,3-dihydroquinazolin-4(1 H )-ones that are the scaffold of Retro-2 cycl , we found that enantioselective reaction of 5-methylthiophene-2-carboxaldehyde with 2-aminobenzanilide using the readily available Sc(III)-inda-pybox as a catalyst11 gave the desired product with <10% yield and ~20% enantiomeric excess. Recognizing the presence of the aniline moiety in Retro-2 cycl , we wanted to perform fractional crystallization of (±)-Retro-2 cycl salts to be prepared from chiral acids.…”

BF3‐grafted Fe3O4@Sucrose nanoparticles as a highly‐efficient acid catalyst for syntheses of Dihydroquinazolinones (DHQZs) and Bis 3‐Indolyl Methanes (BIMs)

“…2.80 and 2.35 mmol H + per each gram catalyst were final amounts of releasing proton (primary number of capacity is equal to 3.72) after six runs for DHQZs and BIMs syntheses, respectively. [25] 3 | EXPERIMENTAL…”

“…There are numerous classical synthetic methods for synthesizing such important compounds using various acids as catalyst like MCM‐41‐Ni coordinated mesoporous, GO nanosheets, Fe 3 O 4 ‐GO and also preliminary endeavors; TiCl 4 ‐Zn, Sc(OTf) 3 , NH 4 Cl, I 2 /KI and solvent as an oxidant, VO(acac) 2 ‐oxidizer, heteropolyacids and T3P™ . In deeper surveys, it is revealed that enantioselective additives also have had an important place for an investigation . Another usual promoter except for alteration of catalyst involves microwave radiation to proceed condensation of Anthranilamide and different carbonyls…”

“…[24] In deeper surveys, it is revealed that enantioselective additives also have had an important place for an investigation. [25] Another usual promoter except for alteration of catalyst involves microwave radiation to proceed condensation of Anthranilamide and different carbonyls. [26] Bis (3-Indolyl) Methanes (BIMs) have attracted considerable interest in recent years due to pharmacological and biological properties.…”

Recent Advances in the Creation of Asymmetric Carbon Centre(s) by Generation of Carbon‐Heteroatom Bond(s) Using Metal‐Pybox Complexes

“…In 2012, studies by Kesavan and Prakash revealed that the use of Sc(III)‐inda‐pybox as the catalyst was effective for the highly enantioselective synthesis of 2,3‐dihydroquinazolinones (DHQZs) (Scheme ) . Best results were obtained when 1 mol% of Sc(OTf) 3 and 2.5 mol% of L 12 were used in CH 2 Cl 2 solvent.…”