Catalytic and Stoichiometric Reactions of the Parent Olefin Rhodium(I) Complex with Alkynes

Abstract

The parent ethylene rhodium(I) complex [(C2H4)2RhCl]2 reacts with internal alkynes to give binuclear metallacycles [(C4R4)Rh2Cl2(C2H4)]2 (R = Me, Et, CH2OMe, Ph), which can act as catalytic intermediates in cyclotrimerization reactions. These metallacycles can be converted into catalytically inert metallocenes CpRh(η5-C4R4RhCp) by addition of CpTl. Further reactions of these metallocenes with [CpRhI2]x and AgBF4 lead to the unique triple-decker complexes [CpRh(μ-C4R4RhCp)RhCp](BF4)2 with metal atoms in the central ring. The structures of all three types of complexes have been established by X-ray diffraction.

Selective Catalysts for the Homogeneous Semi‐Hydrogenation

“…Initially, the typical rhodium diolefin precursors [Rh( μ ‐Cl)(COD)] 2 and [Rh( μ ‐Cl)(NBD)] 2 (NBD=2,5‐norbornadiene) were tested in the hydrogenation of DIP (Figure S3), since recently the catalytic activity of [Rh( μ ‐Cl)(ethene) 2 ] 2 without additional ligand has been demonstrated [9] . Both precursor showed <3% conversion in the hydrogenation of DIP.…”

Enantioselective Synthesis of Dihydrobenzofurans, Dihydrobenzosulfones, and Dihydroindoles by Merging One‐pot Intramolecular Heck‐Matsuda Reactions from Anilines with Redox‐Relay Process

“…Transition metal catalysis remains a valuable tool in organic synthesis due to its versatility, robustness, and efficiency [31] . The palladium‐catalyzed Heck arylations using aryldiazonium salts (Heck‐Matsuda (HM) reaction) are good examples of efficient and reliable processes.…”