Supramolecular ligand–ligand and ligand–substrate interactions for highly selective transition metal catalysis

Abstract

The use of non covalent supramolecular ligand-ligand and ligand-substrate interactions in transition metal-catalysed transformations is a new, rapidly emerging area of research. Non-covalent interactions between monodentate ligands such as hydrogen bonding, coordinative bonding, ion pairing, π-π interactions and the formation of inclusion compounds, have been shown to impart higher activity and chemo-, regio-, and stereoselectivity to the corresponding transition metal complexes in a number of catalytic applications. Analogously, supramolecular ligand-substrate interactions, and particularly hydrogen bonding, have been used to direct the regio- and stereochemistry of several metal-catalysed reactions. The catalytic systems relying on supramolecular interactions are generally capable of self-assembling from simpler components in the environment where catalysis is to take place, and are therefore very well-suited for combinatorial catalyst discovery strategies and high-throughput screening.

Application of Hydroxyporphyrins-based Phosphite-type Ligands to Asymmetric Pd-Catalyzed Allylic Substitution Reactions

“…[2,17,18,32,33] Catalytic systems based on chiral supramolecular ligands with phosphite moiety have recently attracted increasing attention. [34][35][36][37][38] In particular, phosphites and phosphoramidites with BINOL or TADDOL backbone and metalloporphyrin fragment have proven to be highly advantageous building blocks in creating large libraries of supramolecular ligands. [34][35][36][37][38][39][40][41][42][43] However, according to our best knowledge, there is only one brief mention of chiral phosphite bearing porphyrin core without a metal ion.…”

“…[34][35][36][37][38] In particular, phosphites and phosphoramidites with BINOL or TADDOL backbone and metalloporphyrin fragment have proven to be highly advantageous building blocks in creating large libraries of supramolecular ligands. [34][35][36][37][38][39][40][41][42][43] However, according to our best knowledge, there is only one brief mention of chiral phosphite bearing porphyrin core without a metal ion. [40] In this paper, we report on the preparation of a small series of phosphite and diamidophosphite ligands containing metal-free porphyrin framework, that we had subsequently explored in Pd-catalyzed asymmetric allylation reactions.…”

Bidentate ligands templated by a convex trimetallic bis(salphen) platform

“…Supramolecular catalysis is now a mature area that facilitates homogeneous catalysis in the short timeframes imposed on catalyst discovery by industrial needs [1][2][3][4]. Construction of catalysts based on multiple non-covalent interactions permits the rapid synthesis of wide ranges of new ligands, thus accelerating the discovery process.…”

Metal compounds with rigid polyaromatic ligands. Catalytic consequences

“…Deprotonation of an azolium salt with a strong base such as NaH or KO t Bu renders the free carbene, 9,15,29 which can then be reacted with a suitable transition metal complex to yield the NHC metal complex.…”

“…[28][29][30] Also, due to its fluorescence properties, pyrene is the chromophore of choice in fundamental and applied photochemical research, 21 thus its incorporation into NHC ligands may add interesting photophysical applications to their derived compounds.…”