Catalytic Efficiency of Primary β‐Amino Alcohols and Their Derivatives in Organocatalysis

Abstract

Chiral primary β‐amino alcohols, constuting adjacently positioned Brønsted base and Brønsted acid sites, are emerging as very valuable bifunctional organocatalysts in a wide array of asymmetric organic transformations. Primary β‐amino alcohols represent inexpensive alternatives to other primary amino organocatalysts such as chiral diamines and cinchona‐alkaloid‐derived primary amines, being easy to synthesize and air‐stable and offering the potential for introduction of different functional groups and also for alteration of steric sites. Here we reveal the catalytic use of simple primary β‐amino alcohols and their derivatives as organocatalysts in Diels–Alder cycloaddition, aldol condensation, Michael addition, 1,3‐dipolar cycloaddition, the Morita–Baylis–Hillman reaction, cascade cyclization, allylation of isatins, Friedel–Crafts alkylation and epoxidation of olefins.

Asymmetric organocatalyzed synthesis of coumarin derivatives

“…Although chiral secondary amines have proved to be particularly useful catalysts, primary amines as organocatalysts in asymmetric synthesis have also played a significant role [ 36 ]. For instance, Kim et al described the enantioselective Michael addition of 4-hydroxycoumarin ( 1 ) by the Re face of the enones 2 through a bifunctional modified binaphthyl organocatalyst 18 with primary amine [ 37 ].…”

Catalytic Formation of Silicon–Heteroatom (N, P, O, S) Bonds

“…have expanded the application of B(C 6 F 5 ) 3 to the double hydrosilylation/reduction of conjugated nitriles . This is a very interesting route, because it allows β‐silylamines to be obtained, and they can subsequently be converted into β‐amino alcohols (Scheme ), which are very interesting molecules owing to their biological and chemical activity …”

Simple primary β-amino alcohols as organocatalysts for the asymmetric Michael addition of β-keto esters to nitroalkenes

“…This amino alcohol X contains an amino group acting as a basic or covalent enamine formation site, a non-covalent hydroxyl group acting as a hydrogen bonding site in a single molecule and also the substituents at α- and β-positions, which might also be effective in controlling the enantioselective reaction course ( Scheme 1 ). In our previous study, this catalyst has worked as an efficient organocatalyst in 1,3-dipolar cycloaddition, 4 Diels–Alder reactions 5 and aldol reactions. 6 Asymmetric Michael addition is recognized as a versatile and powerful key carbon–carbon bond and also a powerful tool for constructing carbon–heteroatom bond providing an effective route for the synthesis of chiral compounds which act as precursor for a range of biologically and pharmaceutically important compounds.…”