Reactivity of Rare Earth Metal Alkyl Complexes with Nitriles or Isonitrile: Versatile Ways toward Multiply Functionalized β-Diketiminato, (Iso)indolyl, and Imidazolyl Chelating Rare Earth Metal Complexes.

The reactivity of the rare earth metal alkyl complexes RE(CHSiMe)(THF) () [RE = Y (), Yb (), Lu (); = 2,5-[(2-pyrrolyl)CPh](-methylpyrrole)] with various nitriles and isonitriles has been fully developed. Treatment of the yttrium monoalkyl complex () with 2 equiv of aromatic nitriles afforded the symmetric trisubstituted β-diketiminato yttrium complexes (, , and through successive cyano group insertion into the RE-C bond and 1,3-H shift or the unsymmetric trisubstituted β-diketiminato yttrium complex () unexpectedly via a 1,3-SiMe shift when 4-(trifluoromethyl)benzonitrile was used in this reaction under the same conditions. By treating with 2 equiv of tolyl acetonitrile, an activation of the C-H bond occurred to form the corresponding β-aryl keteniminato complexes and .

Synthesis and catalytic activity of tetradentate β-diketiminato rare-earth metal monoalkyl complexes in tandem Oppenauer oxidation and cross-aldol condensation.

A series of unsymmetric tetradentate β-diketiminato rare-earth metal monoalkyl complexes were synthesized, and their catalytic behavior has been well developed. Indole-incorporated β-diketiminato proligands HL (L = MeC(NDipp)CHC(Me)NCHCH-3-(1-R-CHN), R = CH-(2-CHO), L1; R = (CH)OMe, L2; Dipp = 2,6-PrCH) were prepared by the reaction of an arylamino-enone with 1-substituted-tryptamine in good yields. Treatment of the proligands with the rare-earth metal trialkyl complexes RE(CHSiMe)(THF) generated the corresponding unsymmetric ,,,-tetradentate β-diketiminato rare-earth metal monoalkyl complexes LRE(CHSiMe) (L1, RE = Y (1a), Gd (1b), Yb (1c), Lu (1d); L2, RE = Y (2a), Gd (2b), Yb (2c), and Lu(2d)).

Pictet-Spengler synthesis of twisted quinoline-fused BODIPYs as heavy-atom-free photosensitizers.

Singly and doubly quinoline-fused BODIPYs were effectively synthesized through a reaction sequence consisting of the reduction of nitrophenyl-substituted BODIPYs and subsequent Pictet-Spengler cyclization. The combination of the BODIPY core and fused quinoline rings imposed significantly twisted conformations in the quinoline-fused BODIPYs (around 20.0° deviation from coplanarity obtained from X-ray crystal structure analysis).

Aryl C-H bond functionalization with diphenyldiazomethane induced by rare-earth metal alkyl complexes.

The first examples of regioselective aryl -C-H functionalization with diphenyldiazomethane for the construction of C-N bonds were accomplished the activation of C-H bonds and the subsequent reaction of diphenyldiazomethane with the RE-C bond. The reactions of rare-earth metal monoalkyl complexes LRE(CHSiMe)(THF) (L = 2,5-[(2-pyrrolyl)CPh](-Me-pyrrole)) supported by a neutral -methylpyrrole anchored dipyrrolyl ligand with 2 equiv. of PhCN gave irreversibly unprecedented hydrazonato-functionalized imino rare-earth metal complexes LRE(PhCNNCH-(-CNHPh) (RE = Y (2a), Lu (2a')) in good yields involving a rather complex process including the interaction of a diazo unit with a RE-C bond, a β-H elimination, a N-N cleavage, 1,4-hydrogen transfer and the subsequent C-N coupling with another diphenyldiazomethane.

Rare-Earth-Metal-Complex-Catalyzed Hydroalkoxylation and Tandem Hydroalkoxylation/Cyclohydroamination of Isocyanates: Synthesis of Carbamates and Oxazolidinones.

Novel N,N,N-tridentate β-diketiminato rare-earth-metal dialkyl complexes RE(CHSiMe) [RE = Y (), Gd (), Yb (), Lu (); = MeC(NDipp)CHC(Me)N(CH)NCH, where Dipp = 2,6-PrCH] have been conveniently synthesized by one step from reactions of the rare-earth-metal trialkyl complexes RE(CHSiMe)(THF) (THF = tetrahydrofuran) with a pyrrolidine-functionalized β-diketiminate H, and their catalytic behaviors toward hydroalkoxylation and tandem hydroalkoxylation/cyclohydroamination of isocyanates have been described. These rare-earth-metal catalysts exhibited high efficiency in the hydroalkoxylation of isocyanates, providing a variety of -alkyl and -aryl carbamate derivatives under mild reaction conditions with a rather low catalyst loading (0.04 mol %).

Dehydrogenative Coupling of Terminal Alkynes with O/N-Based Monohydrosilanes Catalyzed by Rare-Earth Metal Complexes.

Newly synthesized rare-earth metal alkyl complexes bearing a tripyrrolyl ligand act as excellent precatalysts for the cross-dehydrogenative coupling between various terminal alkynes and O/N-based monohydrosilanes of HSi(OEt)/HSi(NMe), leading to the formation of a variety of alkoxysilylalkyne and aminosilylalkyne derivatives in good to high yields. The precatalysts RE(CHSiMe)(thf) (RE = Y(), Er(), Yb(), = 2,5-[(2-CHN)CPh](CHNMe), thf = tetrahydrofuran) were easily prepared in high yields via the reactions of RE(CHSiMe)(thf) with the proligand H in a single step. Mechanistic studies reveal that treatment of with phenylacetylene could generate the active catalytic species: dinuclear rare-earth metal alkynides ((thf)[RE(μ-C≡CPh)]) (RE = Y(), = 1; Yb(), = 0), which could react with HSi(OEt) to produce the coupling product and the dinuclear rare-earth metal hydrides ( (thf)[RE(μ-H)]) (RE = Y(); Yb()).

Versatile reactivities of rare-earth metal dialkyl complexes supported by a neutral pyrrolyl-functionalized β-diketiminato ligand.

Herein, rare-earth metal dialkyl complexes supported by a neutral pyrrolyl-functionalized β-diketiminato ligand with the formula LRE(CHSiMe)(thf) (RE = Y (1a), Dy (1b), Er (1c), Yb (1d); L = MeC(NDipp)CHC(Me)NCHCHNCH-2,5-Me, Dipp = 2,6-PrCH) were synthesized via the reactions of the β-diketimine HL with the rare-earth metal trialkyl complexes RE(CHSiMe)(thf) in high yields. The reactivities of 1 with pyridine derivatives, unsaturated substrates, and elemental sulfur were investigated, and some interesting chemical transformations were observed. Ligand exchange and activation of sp and sp C-H bonds occurred during the reactions with pyridine derivatives to afford different types of mononuclear rare-earth metal pyridyl complexes, namely, LEr(CHSiMe)(η-NCH) (2c), LRE(η-CH-2-NCH-4,6-Me) (RE = Y (3a), Er (3c)), and LRE(CHSiMe)(η-(C,N)-2-(2-CHNCH)) (RE = Er (4c), Yb = (4d)).