The last decade has witnessed wonderful and remarkable advances in the chemistry of early actinides, providing information on not only the reactivity of these types of compounds in stoichiometric reactions but also their utilization in challenging catalytic processes. This canvas of knowledge allows the design of chemical reactivities to reach a high level of sophistication. As compared to early/late transition metal and lanthanide complexes, the actinides display complementary and in some cases real unique performances for similar organic transformations. The study of organoactinides allows us to design new chemical transformations due to their distinctive electronic structures, which feature a large coordination number exhibiting steric interactions. This review highlights the latest results obtained since 2008 on the catalytic activities of organoactinides. This review presents a brief introduction, and two main parts: (i) organoactinide mediated catalytic transformations of small molecules, including hydroelementation, coupling reactions, etc.; (ii) organoactinide catalysed polymerization and oligomerization reactions, including olefin, diene, cyclic ester and epoxide substrates. At the end, we present our Quo Vadis opinion and pose some challenging questions and our personal opinion regarding where this field should continue to develop.

A novel class of ligand systems possessing a sixmembered N-heterocyclic iminato [perimidin-2-iminato (Pr R N, where R = isopropyl, cycloheptyl)] moiety is introduced. The complexation of these ligands with early actinides (An = Th and U) results in powerful catalysts [(Pr R N)An(N{SiMe 3 ) 2 } 3 ] (3−6) for exigent insertion of alcohols into carbodiimides to produce the corresponding isoureas in short reaction times with excellent yields. Experimental, thermodynamic, and kinetic data as well as the results of stoichiometric reactions provide cumulative evidence that supports a plausible mechanism for the reaction.

Changing the N-substituents of a methylene-linked bis-NHC ligand from n-butyl to bulky mesityl shifts ligand coordination from normal/ normal to normal/abnormal mode. The mesityl wingtip groups afford [Ru II ( Mes NHC(CH 2 )NHC Mes )( Mes NHC(CH 2 )aNHC Mes )(CH 3 CN) 2 ][PF 6 ] 2 (1), in which one of the ligands exhibits mixed C 2 /C 4 binding to the same metal, while the second ligand utilizes C 2 /C 2 carbons for metal coordination. On the contrary, the n-butyl analogue leads to metal oxidation, affording a Ru III complex [Ru( nBu NHC(CH 2 )NHC nBu ) 2 Cl 2 ][PF 6 ] (2) upon crystallization in air, where both ligands show normal C 2 /C 2 coordination. Thus, the resulting complexes exhibit different structural and electronic characteristics, which are further reflected in their catalytic responses. The catalytic utilities of both compounds toward carboxylic acid addition onto terminal alkyne are evaluated in this work. The abnormally bound 1 shows higher activity and better selectivity compared to all-normal counterpart 2.

Ferrocene-amide-functionalized 1,8-naphthyridine (NP) based ligands {[(5,7-dimethyl-1,8-naphthyridin-2-yl)amino]carbonyl}ferrocene (L(1) H) and {[(3-phenyl-1,8-naphthyridin-2-yl)amino]carbonyl}ferrocene (L(2) H) have been synthesized. Room-temperature treatment of both the ligands with Rh2 (CH3 COO)4 produced [Rh2 (CH3 COO)3 (L(1) )] (1) and [Rh2 (CH3 COO)3 (L(2) )] (2) as neutral complexes in which the ligands were deprotonated and bound in a tridentate fashion. The steric effect of the ortho-methyl group in L(1) H and the inertness of the bridging carboxylate groups prevented the incorporation of the second ligand on the {Rh(II) -Rh(II) } unit. The use of the more labile Rh2 (CF3 COO)4 salt with L(1) H produced a cis bis-adduct [Rh2 (CF3 COO)4 (L(1) H)(2) ] (3), whereas L(2) H resulted in a trans bis-adduct [Rh2 (CF3 COO)3 (L(2) )(L(2) H)] (4). Ligand L(1) H exhibits chelate binding in 3 and L(2) H forms a bridge-chelate mode in 4. Hydrogen-bonding interactions between the amide hydrogen and carboxylate oxygen atoms play an important role in the formation of these complexes. In the absence of this hydrogen-bonding interaction, both ligands bind axially as evident from the X-ray structure of [Rh2 (CH3 COO)2 (CH3 CN)4 (L(2) H)2 ](BF4 )2 (6). However, the axial ligands reorganize at reflux into a bridge-chelate coordination mode and produce [Rh2 (CH3 COO)2 (CH3 CN)2 (L(1) H)](BF4 )2 (5) and [Rh2 (CH3 COO)2 (L(2) H)2 ](BF4 )2 (7). Judicious selection of the dirhodium(II) precursors, choice of ligand, and adaptation of the correct reaction conditions affords 7, which features hemilabile amide side arms that occupy sites trans to the Rh-Rh bond. Consequently, this compound exhibits higher catalytic activity for carbene insertion to the CH bond of substituted indoles by using appropriate diazo compounds, whereas other compounds are far less reactive. Thus, this work demonstrates the utility of steric crowding, hemilability, and hydrogen-bonding functionalities to govern the structure and catalytic efficacyof dirhodium(II,II) compounds.

Here we present an unprecedented chemoselective hydroboration for aldehydes and ketones catalysed by actinides. The reaction features a very low catalyst loading (0.1-0.004 mol%) and quantitative product formation in less than 15 minutes, at room temperature. Thermodynamic and kinetic studies including stoichiometric and labeling studies with deuterated pinacolborane allow us to propose a plausible mechanism for this remarkable catalytic regeneration of a Th-H bond via carbonyl hydroboration.