TADDOL-based phosphorus(iii)-ligands in enantioselective Pd(0)-catalysed C–H functionalisations

Abstract

Monodentate TADDOL-derived phosphoramidites and phosphonites are versatile chiral ligands for enantioselective Pd(0)-catalysed C-H functionalisations. They enable highly selective cyclisations to access a wide range of chiral carbo- and heterocycles. The high attractiveness of this ligand class consists in their modular structure, allowing for a quick assembly of a library with variable steric properties. Asymmetric C-H functionalisation methods utilising catalytic systems based on Pd(0) complexes and TADDOL-type ligands are presented and aspects of selectivity are discussed.

Bulky Substituent Effect on Reactivity of Localized Singlet Cyclopentane‐1,3‐diyls with π‐Single Bonding (C‐π‐C) Character

“…[1][2][3][4] The steric effect has been known to influence stereoselectivity in asymmetric syntheses. [5][6][7][8] Kinetic stabilization induced by steric hindrance has also played ac rucial role in stabilizing and isolating low-valent compounds. [9][10][11] It is essential for understanding the steric effect on fundamental reactions.…”

Accelerated and Enantioselective Synthesis of a Library of P‐Stereogenic Urea Phosphines

“…Metal catalyzed asymmetric reactions have established themselves as powerful synthetic tools to construct an array of enantiomerically enriched compounds, in which phosphines play a leading role These phosphine ligands create a regulated microenvironment around the metal center during the asymmetric transformation, which in turn governs the regio‐ and stereoselectivity of the reaction , . Depending on the requirements of a reaction, monodentate, bidentate, and multidentate chiral phosphorus ligands have been utilized . The bidentate phosphorus ligands can form strong chelate with metal center and create specific bite angle that engages the space around metal center.…”

Ligand‐Enabled Enantioselective C–H Activation of Tetrahydroquinolines and Saturated Aza‐Heterocycles by RhI

“…[14] Thec ombination of ac hiral phosphoramidite and aR h I catalyst has only found its application in C sp 2 -H activation reactions for intramolecular hydroarylation. [15] Nitrogen-containing,s aturated heterocyclic compounds are commonly found in natural products,drugs,and pharmaceuticals. [20] They are without doubt one of the most important compound classes in the pharmaceutical industry.…”

“…Therefore,the substituent adjacent to the phosphorus atom in the ligand was investigated. Ligands with aseries of different alkyl and aryl moieties having distinct steric and electronic properties were tested (entries [6][7][8][9][10][11][12][13][14][15][16]. L9 was found to be the optimal ligand in this transformation.…”