One‐Pot Synthesis of Fused Tetrahydroquinoline‐Iminosugar Derivatives

Abstract

An efficient and simple one‐pot synthesis of structurally diverse novel tetrahydroquinolin fused iminosugars was developed through the aza‐Diels‐Alder mechanism. The adaptability of this method has been demonstrated by a variety of imines and D/L‐ribose tosylates, and both electron‐donating and withdrawing substituted imines are employed in reaction well. In addition, this reaction is characterized by simple operation, good yield, and high atom economy. Some synthetic iminosugars showed moderate anti proliferation of HCT116 tumor cells.

A Tandem Aldol Condensation/Diels‐Alder Sequence of Reactions for One‐Pot Synthesis of a New Series of Polysubstituted‐Decalines

“…, [13] leading to efficient synthesis of pharmaceuticals, [14] natural products, [15] and other molecules of choice. [16] Illustrative multicomponent syntheses involving a DA reaction as the key step include a tandem sequential double DA/ Nazarov reaction in an unsymmetrically substituted diynone to yield a tricyclic scaffolds (such as taiwaniaquinol D), [17] the synthesis of chromenoquinolones via an imine formation/aza-DA/aromatization tandem process, [18] a sequence of DA and intramolecular [3 + 2] cycloadditions of dienylcyclopropane 1,1diesters for rapid construction of fused carbocyclic structures (such as brussonol), [19] a domino Knoevenagel-hetero-DA reaction to access various chromenones, [20] a twelve-step synthetic rout, having the DA reaction as the key step, to the structural core of aflavinines, [21] synthesis of ring-fused 2-cyclopentenone moieties, found in the skeleton of many natural and bioactive compounds like helenalin, via a gold-catalyzed cycloisomerization/hetero-DA/ring-opening sequence of tandem reactions of enynyl acetates, [22] an organocatalyzed sequence of oxa-Michael/Michael/Michael/aldol condensation reactions followed by an intramolecular DA cycloaddition leading to asymmetric synthesis of functionalized tricycles, [23] asymmetric multicomponent synthesis of bioactive alkaloid-type polycycles through catalytic aza-DA reaction of indoles having oxetane as the directing group, [24] and a tandem aldol condensation-DAaromatization sequence of reactions to access 2-tetralones (like serteraline) [25] [Figure 1].…”

Synthesis of 3-arylamino-2-polyhydroxyalkyl-substituted indoles from unprotected saccharides and anilines

“…Combined with our prior experiences in the reactions of sugars and aromatic amines, 14 the effective approach to indoles employed Sc(OTf) 3 as a catalyst in acetonitrile at 80 °C using various aromatic amines and unprotected sugars as starting materials. Initially, l -rhamnose and aniline were selected as model substrates to optimize the reaction conditions (Table 1).…”