Synthesis and catalytic activity of palladium complexes bearing N-heterocyclic carbenes (NHCs) and 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane (CAP) ligands

Abstract

The synthesis and characterization of novel palladium complexes bearing N-heterocyclic carbenes (NHCs) and 1,4,7-triaza-9-phosphatricyclo [5.3.2.1] tridecane (CAP) are reported. These organometallic complexes can be easily obtained using two different synthetic...

Synthesis and Characterization of Novel [2 + 1] Tricarbonyl Rhenium Complexes with the Hydrophilic Phosphine Ligands PTA and CAP

“…This abnormal behavior is also reflected to the CAP derivatives 1b-3b . As shown in Table 2 , their 31 P resonances are displaced upfield which is unusual among phosphane ligands but is also observed for other CAP complexes [ 12 ]. All complexes reported herein show a single 31 P peak demonstrating the absence of isomers, as expected.…”

“…A further feature that makes CAP particularly interesting is its stereoelectronic properties. CAP combines strong electron-donating ability with an extremely reduced steric hindrance (cone angle = 109°) [ 12 ] making this phosphine ligand unique compared to more classical tertiary phosphines.…”

Synthesis, characterization, and reactivity of [Pd(phosphine)(py)Cl2] (PEPPSI) and [Pd(phosphine)Cl2]2complexes

“…The longer reaction time (usually 24 h) is attributed to the high ligand steric bulkiness as we have previously observed that the much smaller CAP ligand required only 15 minutes to complete this ligand substitution. 32 An alternative synthetic route to such compositions was explored starting from PdCl 2 (Scheme 1, Method B). However, for the reaction to proceed, the reaction temperature had to be raised to 60 °C and the operational solvent had to be changed to chloroform.…”

“…31 Another example is the use of the CAP (1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane) ligand in the context of a PEPPSI architecture which did not display any reactivity in C-N coupling. 32 Therefore we were eager to investigate such complexes with more commonly utilized Buchwald biaryl phosphine ligands. Herein we report the synthesis, characterization and catalytic activity in C-N coupling of a series of phos-phine palladium PEPPSI and chloride dimer complexes bearing the known Buchwald ligands, RuPhos, SPhos and XPhos, as ancillary ligands.…”

Synthesis of New Ruthenium‐CAP Complexes and Use as Catalysts for Benzonitrile Hydration to Benzamide

“…Recently, Britvin and coworkers reported the synthesis of the new cage-like water soluble phosphine 1,4,7-triaza-9phosphatricyclo[5.3.2.1]tridecane, to which they gave the acronym of CAP (Figure 1). [26] Although examples of CAP complexes of Au, [26a] Pt and Pd, [27,28] Tc and Re, [29] and Rh [30] were reported, its coordination chemistry with Ru is still underdeveloped. We recently reported the synthesis of the Ru-arene CAP complexes [RuCl 2 (η 6 -p-cymene)(CAP)] (RACAPÀ C) and [RuCl (η 6 -p-cymene)(L)(CAP)]PF 6 (L = CAP or MeCN), that showed to be active in vitro anticancer agents.…”