A highly selective (>99%) tandem catalytic system for the conversion of ethanol (up to 37%) to n-butanol, through the Guerbet process, has been developed using a bifunctional iridium catalyst coupled with bulky nickel or copper hydroxides. These sterically crowded nickel and copper hydroxides catalyze the key aldol coupling reaction of acetaldehyde to exclusively yield the C4 coupling product, crotonaldehyde. Iridium-mediated dehydrogenation of ethanol to acetaldehyde has led to the development of an ethanol-to-butanol process operated at a lower temperature.

(1c), were prepared and the electronic structure of the oneelectron oxidized species [1a-c] + were investigated in solution. The solid-state structures of 1a and 1b were solved by X-ray crystallography, and in the case of 1b an asymmetric UO2 2+ unit was found due to an intermolecular hydrogen bonding interaction. Electrochemical investigation of 1a-c by cyclic voltammetry showed that each complex exhibited at least one quasi-reversible redox process assigned to the oxidation of the phenolate moieties to phenoxyl radicals. The trend in redox potentials matches the electron-donating ability of the para-phenolate substituents. The electron paramagnetic resonance spectra of cations

The synthesis and characterization of a series of new diamido-thorium(IV) and diamido-uranium(IV) halide and alkyl complexes supported by three different diamido-ether ligands are reported. Reaction of ThCl 4 •2DME with [(RNSiMe 2 ) 2 O]Li 2 ([ R NON]Li 2 ) in DME when R = t Bu gives [ tBu NON]-ThCl 5 Li 3 •DME (1), when R = i Pr 2 Ph in diethyl ether [ iPr 2 Ph NON]-ThCl 3 Li•DME (3) is prepared. Reaction of UCl 4 with [ iPr 2 Ph NON]-Li 2 in diethyl ether gives {[ iPr 2 Ph NON]UCl 2 } 2 (4). Reaction of ThCl 4 •2DME with Li 2 [( i Pr 2 PhNCH 2 CH 2 ) 2 O] ([ iPr 2 Ph NCOCN]-Li 2 ) in DME gives [ iPr 2 Ph NCOCN]ThCl 2 •DME (5). The addition of 2 equiv of LiCH 2 SiMe 3 to 1 and 5 resulted in salt-and basefree [ tBu NON]Th(CH 2 SiMe 3 ) 2 ( 7) and [ iPr 2 Ph NCOCN]Th(CH 2 SiMe 3 ) 2 (9), respectively. Complexes 1, 3, 4, 7, and 9, as well as previously reported {[ tBu NON]UCl 2 } 2 (2), [ tBu NON]U(CH 2 SiMe 3 ) 2 ( 6), and [ iPr 2 Ph NCOCN]U(CH 2 SiMe 3 ) 2 (8) were examined as catalysts for the intramolecular hydroamination of a series of aminoalkenes. Complexes 6−9 were shown to facilitate the formation of 2-methyl-4,4-diphenylpyrrolidine from 2,2-diphenyl-1-amino-4-pentene at room temperature. For 9, this reaction occurs in less than 15 min, while for other dialkyls 6−8, the reaction takes less than 2 h. Dihalides 1 and 2 facilitated the same reaction at 60 °C in 4 h, while 3 and 4 showed no activity under the same conditions. Dialkyl complexes 7−9 were examined for further reactivity with different substrates. The uranium dialkyl 8 was more active than 7 and 9 for the cyclization of 2,2-diphenyl-1-amino-5-hexene and 2,2-diphenyl-1-amino-6-heptene, as well as more active in the cyclization of N-methyl-2,2diphenyl-1-amino-4-pentene, a secondary amine. All three dialkyls became less active when the steric bulk of the gem-substituents was decreased from diphenyl to cyclopentyl; reactivity further decreased when the steric bulk of the substituents was decreased further to hydrogen.

The synthesis and characterization of two new uranium(IV) dialkyl complexes supported by two different diamido ether ligands are reported. The reaction of) with 2 equiv of KCH 2 Ph generates the organoactinide [{ dipp NCOCN}U(CH 2 Ph) 2 ] (3), which shows an η 1 -, η 2 -benzyl arrangement of the alkyl ligands in the solid state. Reaction of) with 2 equiv of LiCH(SiMe 3 ) 2 yields the alkyl-bridged uranium dimer [{ tBu NON}U{CH(SiMe 3 )(SiMe 2 CH 2 )}] 2 (4), which forms via γ C-H activation of the CH(SiMe 3 ) 2 substituent. Reaction of 3 and 4 as well as previously reported [{ tBu NON}U(CH 2 SiMe 3 ) 2 ] (1) and [{ dipp NCOCN}U(CH 2 SiMe 3 ) 2 ] (2) with 1 atm of ethylene under ambient conditions produced high molecular weight polymers, demonstrating that diamido ether actinide complexes can act as ethylene polymerization catalysts; activities up to 560 g/mol 3 h 3 atm using 1 were observed. Reaction of 1 and 2 with 1 atm of ethylene and 1 equiv of B(C 6 F 5 ) 3 demonstrated a 4-fold decrease in activity of the catalyst. Reaction of 1 or 2 with an excess of MMAO or Et 2 AlCl did not yield any polymer formation upon the addition of ethylene. After reaction of 1 with Et 2 AlCl, removal of volatiles in vacuo yielded a dark red liquid that, upon standing, formed green crystals of [{ tBu NON}U{(μ-Cl) 2 AlEt 2 } 2 ] (5), indicating a route for catalyst deactivation by aluminum-based cocatalysts.