Abstract
Organocatalytic, asymmetric Mannich reactions giving β3-amino acid derivatives have been reviewed. The Mannich-type addition of an acetate anion to an imine represents in fact one of the most direct routes to this particular class of β-amino acids. However, due to the low acidity of simple acetates, synthetic equivalents of acetate anions had to be used. These include preformed enolates (silylketeneacetals), carbonylic compounds with improved reactivity (acetophenones and their enamines/enamides), acetates equipped with a removable group enhancing their acidity (malonates, nitroacetates, sulfonylacetates, diazoacetates), acetates able to undergo decarboxylative enolate formation (malonic acid half thioesters), and finally acetaldehyde. Each of these equivalents was combined with the requisite organocatalytic strategy, giving very powerful and effective methods for the preparation of β3-amino acid precursors. The simple and straightforward manipulations, used to convert these products into the target β3-amino acid compounds, are also described.
Keywords: Acetate anion, β-amino acid, asymmetric catalysis, imine, Mannich reaction, organocatalysis, enantioselectivity, (Ee) Enantiomeric excess, (MAHT) Malonic acid half thioester, (Pg) Protecting group, (PTC) Phase-transfer catalysis, (Rfx) Reflux, (Ts) p-toluensulfonyl, MALONIC ACID HALF THIOESTERS 11, Alanine (homoglycine), peptidase enzymes
Call for Papers in Thematic Issues
Advances of Heterocyclic Chemistry with Pesticide Activity
Global food safety and security will continue to be a global concern for the next 50 years and beyond. Plant diseases have had a significant impact on food safety and security throughout the entire food chain, from primary production to consumption. While conventional chemical pesticides have been traditionally used for ...read more
Calculation design of covalent/metal organic framework based catalysts
This research area combines theoretical computation and screening with machine learning for the design of covalent/metal organic framework-based catalysts, bridging the disciplines of organic chemistry, physical chemistry, computational chemistry, materials science, and machine learning. It covers several critical aspects: designing and synthesizing organic catalysts for improved performance, applying computational methods ...read more
Carbohydrates conversion in biofuels and bioproducts
Biomass pretreatment, hydrolysis, and saccharification of carbohydrates, and sugars bioconversion in biofuels and bioproducts within a biorefinery framework. Carbohydrates derived from woody biomass, agricultural wastes, algae, sewage sludge, or any other lignocellulosic feedstock are included in this issue. Simulation, techno-economic analysis, and life cycle analysis of a biorefinery process are ...read more
Catalytic C-H bond activation as a tool for functionalization of heterocycles
The major topic is the functionalization of heterocycles through catalyzed C-H bond activation. The strategies based on C-H activation not only provide straightforward formation of C-C or C-X bonds but, more importantly, allow for the avoidance of pre-functionalization of one or two of the cross-coupling partners. The beneficial impact of ...read more
Related Books
Advances in Organic Synthesis
The Synthetic Methods, Structures, and Properties of the Ca-C σ Bond Organocalcium Containing Compounds
Advances in Organic Synthesis
Chemistry of Bipyrazoles: Synthesis and Applications
Advances in Organic Synthesis
Advanced Nanocatalysis for Organic Synthesis and Electroanalysis
Advances in Organic Synthesis
Advances in Organic Synthesis
11