Phosphapalladacycles: preparation routes

Abstract

The review considers methods of synthesis of cyclo-The review considers methods of synthesis of cyclopalladated compounds of the PC-and PCP-type including intra-palladated compounds of the PC-and PCP-type including intramolecular activation of the C molecular activation of the C7 7H bonds in the P-donor ligands, H bonds in the P-donor ligands, oxidative addition of preliminarily functionalised substrates to oxidative addition of preliminarily functionalised substrates to palladium( palladium(0 0), transmetallation of lithiated compounds, chelation), transmetallation of lithiated compounds, chelation of phosphine-substituted phosphorus ylides, and some non-stand-of phosphine-substituted phosphorus ylides, and some non-standard processes resulting in a new ligand formation on a metal ard processes resulting in a new ligand formation on a metal template. Particular attention has been given to the structural template. Particular attention has been given to the structural factors and experimental conditions that determine the feasibility factors and experimental conditions that determine the feasibility of direct cyclopalladation of mono-and bidentate phosphines, of direct cyclopalladation of mono-and bidentate phosphines, phosphites and phosphinites. The bibliography includes 384 phosphites and phosphinites. The bibliography includes 384 references. references.

Mechanistic Studies of SCS-Pd Complexes Used in Heck Catalysis

“…If the palladacycle formation were complete (i.e., if there was no coordination complex 5 present), the S-aryl SCS palladacycles (6,7,8,9, 10, 12, or 13) could be used in Heck chemistry without formation of any visible palladium black. If the coordination complex were present as a mixture with the palladacycle or if the coordination complex itself were used, palladium black invariably formed.…”

“…[6] Palladacycles are the palladium subset of this larger group of metallacycles and have been used to promote Pd-catalyzed cross-coupling reactions. [7] Palladium pincer compounds are characterized by a metal-carbon bond and two coordinating heteroatoms that chelate the metal in a cyclic fashion (e.g., 1 -3). The most common heteroatoms are P, N, and S. The SCS palladacycles discussed here were first described by Shaw [8] and they and their N-and P-substituted analogues have emerged as an interesting, actively investigated family of organometallic complexes that have been used as a palladium source for various catalytic reactions.…”

Cyclometalation Using d-Block Transition Metals: Fundamental Aspects and Recent Trends

“…It covers seminal fundamental literature as well as recent highlights and trends that emerged until early 2009, arranged according to the metal involved in the cyclometalation. A significant amount of reviews, books, and book chapters have appeared over the last decades, 6-22 some dwelling on specific metals, 23-28 on specific ligand scaffolds, [29][30][31][32][33][34][35][36][37][38] and on mechanistic aspects. [39][40][41] These compilations may provide useful complementary information on selected issues of cyclometalation.…”

Pincer Complexes with Thione Sulfur Donors

“…A variety of methods for construction of the P-C bonds makes phosphorus-containing groups readily introduced coordinating arms. Generally, organophosphorus ligands are very popular in the creation of pincer complexes, but this concerns mainly various trivalent phosphorus derivatives [4,[15][16][17][18][19][20][21][22][23][24][25][26]. Nevertheless, recent studies on organothiophosphorus pincer systems have led to a considerable progress in this area, and a great diversity of bis(thiophosphoryl) pincer complexes with a benzene, toluene, pyridine, pyrrole, indene, and indole central core featuring promising luminescence properties, intriguing chemical behavior, as well as remarkable catalytic activity in different processes have been developed.…”

“…However, over the years, a classical structure of a pincer ligand has been significantly modified, and different groups, including phosphinite, imine, thioamide, etc., as well as heterocyclic fragments, were successfully introduced as coordinating arms into a pincer framework, extending the boundaries of pincer chemistry. While phosphorus-and nitrogen-donor systems have been extensively reviewed [4,[15][16][17][18][19][20][21][22][23][24][25][26][27][28], their sulfur-containing analogs of S,E,S-types (E¼C, N, P) received markedly less attention. However, the main achievements in the field of thioetherbased sulfur-donor systems have been summarized by P. Le Floch and N. Mézailles [29].…”