Towards Tartaric‐Acid‐Derived Asymmetric Organocatalysts

Abstract

Tartaric acid is one of the most prominent naturally occurring chiral compounds. Whereas its application in the production of chiral ligands for metal-catalysed reactions has been exhaustively investigated, its potential to provide new organocatalysts has been less extensively explored. Nevertheless, some impressive results, such as the use of TADDOLs as chiral H-bonding catalysts or of tartrate-derived asymmetric quaternary ammonium salt catalysts, have been reported over the last decade. The goal of this article is to provide a representative overview of the potential and the limitations of tartaric acid or TADDOLs in the creation of new organocatalysts and to highlight some of the most spectacular applications of these catalysts, as well as to summarize case studies in which other classes of chiral backbones were better suited.

Supramolecular hydrogen-bonding patterns in two cocrystals of the N(7)–H tautomeric form ofN6-benzoyladenine:N6-benzoyladenine–3-hydroxypyridinium-2-carboxylate (1/1) andN6-benzoyladenine–DL-tartaric acid (1/1)

“…The crystal structures of various salts and complexes of 3-hydroxypicolinic acid have also been reported (Karthikeyan et al, 2014;Nirmalram et al, 2011;Betz & Gerber, 2011;Koleša-Dobravc et al, 2014). Tartaric acid has been widely used in food additives (for souring, making wine or as a leavening agent), for making silver mirrors, in the pharmaceutical industry and in catalysis (Luner et al, 2002;Gratzer et al, 2013). Various salts and compounds of tartaric acid have been reported to date (Farrell et al, 2002;Thanigaimani et al, 2007;Smith et al, 2007;Mohandas et al, 2013).…”

Promising Combination for Asymmetric Organocatalysis: Brønsted Acid‐Assisted Chiral Phosphoric Acid Catalysis

“…Generally, it was observed that the bifunctional character of the phosphoric acids, bearing both a Brønsted acidic site and a Lewis basic site, and the neighboring substituents were essential for attaining high levels of enantioselectivity. Intrigued by the incredible advances provided by BINOL‐derived phosphoric acids, several research groups have reported novel chiral phosphoric acids bearing a variety of chiral frameworks, such as TADDOL,2 VAPOL,3 SPINOL,4 and planar skeletons5 (Scheme ). On the other hand, some leading scientists decided to modify the multifunctional units instead (Scheme ), which could drastically alter catalyst performance.…”

Synthesis of l‐threitol‐based crown ethers and their application as enantioselective phase transfer catalyst in Michael additions

“…It has several advantages, being an inexpensive and easily available natural compound; moreover, the L-threitol can be derived from it in an enantiomerically pure form. 26,27 Stoddart performed pioneering work in preparing and investigating macrocycles built up from sugar alcohols such as L-iditol, L-threitol, and D-mannitol. [15][16][17]26,27 At that time, they had not yet studied the catalytic effects of these compounds in phase transfer reactions.…”

“…26,27 Stoddart performed pioneering work in preparing and investigating macrocycles built up from sugar alcohols such as L-iditol, L-threitol, and D-mannitol. [15][16][17]26,27 At that time, they had not yet studied the catalytic effects of these compounds in phase transfer reactions. Later on, a few articles were published on the synthesis of chiral crown ethers derived from diethyl L-tartrate, [28][29][30][31][32][33][34][35][36][37] but from among the macrocycles prepared, only a few were investigated as chiral phase transfer catalysts, which were not too efficient.…”