Development of PNP pincer ligands and their metal complexes via Pd(II)-catalyzed P(III)-C bond formation

• Main Author: Foo, Ce Qing
• Other Authors: Leung Pak Hing
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Science::Chemistry
• Online Access: https://hdl.handle.net/10356/157231
• Institution: Nanyang Technological University

The scene of transition metal catalysis has seen a ubiquitous employment of chiral tertiary phosphines as effective partnering ligand auxiliaries. These are represented in a diverse range of reaction applications, with a plethora of examples illustrating the multifaceted modes of coordination that the phosphine moieties can adopt to suit the requirements of different reactions. To this end, pincer-type tridentate tertiary phosphines have since emerged as a ligand class of its own, facilitating good efficacies in their respective domains of applications yet at the same time providing high stability to the overall complex architecture. Despite these advantageous characteristics, issues associated with their convenient syntheses have remained as a persistent problem particularly for the access towards related asymmetric variants. Herein, asymmetric hydrophosphination is exemplified as a highly viable and effective alternative methodology for the syntheses of optically pure chiral tertiary phosphines, with focus directed specifically at the generation of PN(sp2)P tridentates that have been considerably elusive in the literature. The synthesized diphosphine adducts are further examined for their compatibility in complexation reactions with various transition metal precursors, and a comprehensive discussion is provided to assess the structural characteristics of the furnished complexes.