1,721,032 research outputs found
Enantioselective organocatalytic approaches to active pharmaceutical ingredients – selected industrial examples
No full textCatalysis is, often, the preferred approach to access chiral molecules in enantioenriched form both in academia
and in industry; nowadays, organocatalysis is recognised as the third pillar in asymmetric catalysis, along with
bio- and metal-catalysis. Despite enormous advancements in academic research, there is a common belief that
organocatalysis is not developed enough to be applicable in industry. In this review, we describe a selection of
industrial routes and their R&D process for the manufacture of active pharmaceutical ingredients, highlighting
how asymmetric organocatalysis brings added value to an industrial process. The thorough study of the steps,
driven by economic stimuli, developed and improved chemistry that was, otherwise, believed to not be applicable
in an industrial setting. The knowledge discussed in the reviewed papers will be an invaluable resource
for the whole research community
Diverse exploitation of Brà ̧nsted acid catalysts-paving the way for simple access to enantioenriched amines
No full textRecent advances in the catalytic enantioselective synthesis of primary and secondary amines are highlighted. These reactions are promoted by chiral Bronsted acid catalysts, which maintain their activity even in the presence of basic amine products. More in detail, a conceptually new approach to the kinetic resolution of racemic amines, based on a condensation process, and two transfer hydrogenation reactions of rarely employed N-alkyl and N-H ketimines with Hantzsch esters, are summarised in this article
A new approach for an organocatalytic multicomponent domino asymmetric reaction
No full textAs easy as pouring! Three C-C bonds, up to three stereocenters, and ee values greater than 97% are created in a new organocatalyzed multicomponent domino reaction (see picture; TMS = trimethylsilyl; EWG = electron-withdrawing group). Very high enantioselectivity, control of the substituents, easy handling, and user-friendly reaction conditions are key features of this transformation. (Figure Presented). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA
Impact of Design of Experiments in the optimisation of catalytic reactions in academia
No full textDesign of Experiments (DoE) is extensively and routinely used in industry; however, in the last decades, it has been gaining increasing interest in organic synthesis in academia. The use of Chemometrics is an attractive strategy to find the real optimum in chemical reactions, especially when affected by several variables. DoE has been applied in a growing number of synthetic transformations over the years, where it can undoubtedly help in the process optimisation, saving costs and time. This review concisely discusses the chemometric basis of Design of Experiments and highlights several examples in which DoE has been applied in organic synthesis. Table of contents 1 Introduction 2 Chemometric basis of DoE 3 DoE applied in catalysis: examples 4 Conclusion
Synergistic Organo‐Organocatalysis
No full textAsymmetric organocatalysis is pivotal in the field of asymmetric catalysis and is a crucial technology platform in the industry. However, in some cases, catalysis may have reached its limit and synergistic catalysis is an interesting groundbreaking strategy to go beyond the established limits and perform unprecedented reactions. This type of catalysis does not come without its own challenges; in fact, an appropriate combination of catalysts is required to avoid self-quenching of the catalysts. This chapter will focus on synergistic catalysis mediated by two distinct organocatalysts that act separately to activate the reaction partners. Selected reactions for different types of activations will be discussed, highlighting the development that brought to their discovery
Asymmetric Aminocatalysis-Gold Rush in Organic Chemistry
No full textReview on a very fast moving area of research:
Catalysis with chiral secondary amines (asymmetric aminocatalysis)
has become a well-established and powerful synthetic tool for the
chemo- and enantioselective functionalization of carbonyl
compounds. In the last eight years alone, this field has grown at such an
extraordinary pace that it is now recognized as an independent area of
synthetic chemistry, where the goal is the preparation of any chiral
molecule in an efficient, rapid, and stereoselective manner. This has
been made possible by the impressive level of scientific competition
and high quality research generated in this area. This Review describes
this “Asymmetric Aminocatalysis Gold Rush” and charts the milestones
in its development. As in all areas of science, progress depends
on human effort
Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones
Full text linkCascade cyclocarbopalladation of the readily available aryl/alkyl-substituted propargylic amides containing an aryl iodide moiety, followed by Suzuki–Miyaura coupling with arylboronic acids, allowed an efficient regio- and stereoselective synthesis of tetrasubstituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones. Moreover, cascade cyclocarbopalladation, followed by the reaction with 2-alkynyltrifluoroacetanilides, accomplished a double cyclization to afford challenging 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones bearing a 3-indolyl substituent through aminopalladation/reductive elimination
Organocatalytic Asymmetric Hydrophosphination of α,β-Unsaturated Aldehydes
No full textThe first organocatalytic asymmetric functionalization of aldehydes with a P-based compound has been successfully developed; the use of a simple chiral secondary amine has enabled the highly chemo- and enantioselective conjugate addition of diphenyl phosphine to α,β-unsaturated aldehydes, providing a direct route to chiral β-phosphine aldehyde intermediates. The synthetic utility of the asymmetric hydrophosphination (AHP) strategy was exemplified in a rapid one-pot (two step) synthesis of highly enantioenriched 1,3-aminophoshines, potentially useful P,N-ligands
Boron-Based Lewis Acid Catalysis: Challenges and Perspectives
Full text linkIn the last two decades, boron-based catalysis has been gaining increasing traction in the field of organic synthesis. The use of halogenated triarylboranes as main group Lewis acid catalysts is an attractive strategy. It has been applied in a growing number of transformations over the years, where they may perform comparably or even better than the gold standard catalysts. This review discusses methods of borane synthesis and cutting-edge boron-based Lewis acid catalysis, focusing especially on tris(pentafluorophenyl)-borane [B(C6F5)3], and other halogenated triarylboranes, highlighting how boron Lewis acids employed as catalysts can unlock a plethora of unprecedented chemical transformations or improve the efficiency of existing reactions
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