New Catalytic Performances of Ruthenium and Rhodium Complexes Directed toward Organic Synthesis with High Atom Efficiency

Abstract

Low-valent ruthenium complexes often show intriguing and characteristic catalytic activity for novel organic transformations with high atom efficiency. The design and synthesis of novel low-valent ruthenium complexes having a variety of electron-donating and/or electron-withdrawing ligands is most promising strategy. Several ruthenium catalysts achieved the construction of novel functional organic molecules through cleavage of carboncarbon single bonds, cocyclization of alkynes, alkenes, and/or carbon monoxide, and co-oligomerization of different alkenes without formation of by-products, which meets green and sustainable requirements for organic synthesis in the 21st century. Note that many findings in ruthenium catalysis have opened the door to a new field of rhodium-catalyzed synthetic organic chemistry, represented by cocyclization of alkynes and heterocumulenes.

Lewis Acid Binding and Transfer as a Versatile Experimental Gauge of the Lewis Basicity of Fe0, Ru0, and Pt0Complexes

“…[6] Mononuclear zerovalent Ru 0 complexes appear to be able to catalyze the cyclization of unsaturated organicm oleculeso ri nsertion of unsaturated molecules into CÀHb onds through oxidative coupling of pÀbound ligands, followed by either CÀCr eductivee limination or intramolecular b-hydride elimination processes, respectively. [7][8][9] Mechanistic details on Ru 0 -catalyzed processes are scant, but as with catalysis based on Ru II ,i ti sc lear that traditional oxidative addition/reductive elimination is not predominanti nt his chemistry.…”

Ruthenacyclopentanes as Intermediates in the Regio- and Stereoselective Linear Codimerization ofN-Vinylamides with Electron-Deficient Alkenes

“…Codimerization of alkenes is a promising, atom-efficient synthetic method that affords highly substituted alkenes with various functionalities from simple alkenes. − Thus far, Co, − Ni, − ,,− Ru, − Rh, ,,, Pd, − other transition-metal − complexes, and Lewis or Brønsted acids − have been used as catalysts for this r...…”

Simple and Practical Aerobic Oxidation of Alcohols Catalyzed by a (<i>μ</i>-Oxo)tetraruthenium Cluster

“…We have been interested in ruthenium chemistry, and have successfully synthesized many novel low-valent ruthenium complexes [23,24], which can be used as highly efficient catalysts for characteristic organic synthesis [25,26]. In addition, we have recently succeeded in the synthesis of a novel and isolable (μ-oxo)tetraruthenium cluster (2) [27] by an unusual reaction of a zero-valent ruthenium complex, Ru(η Here, we report that this novel (μ-oxo)tetraruthenium cluster (2) efficiently catalyzes a simple, practical, and selective oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones, respectively, under 1 atm of O 2 or air.…”