Synthesis of a square-planar rhodium alkylidene N-heterocyclic carbene complex and its reactivity toward alkenes

The first rhodium alkylidene square-planar complex stabilized by an N-heterocyclic carbene ligand, RhCl(-CHPh)(IPr)PPh3 (2; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-carbene), has been prepared by reaction of RhCl(IPr)(PPh3)2 (1) with phenyldiazomethane and its dynamic behavior in solution studied. Treatment of 2 with alkenes results in the formation of the ¿2-olefin complexes RhCl(¿2-CH2-CHR)(IPr)PPh3 (3, R = H; 4, R = Ph; 5, R = OEt) and new olefins arising from the coupling of the alkylidene with the alkenes, likely via a metallacyclobutane intermediate

Diethyl carbonate as a solvent for ruthenium catalysed C¬H bond functionalisation

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Synthesis of CF3-Containing 1,2,3,4-Tetrahydroisoquinoline-3-Phosphonates via Regioselective Ruthenium-Catalyzed Co-cyclotrimerization of 1,7-Aza­diynes

International audienceAn efficient access to novel trifluoromethyl-substituted phosphonate analogues of 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (TIC) derivatives based on regioselective ruthenium-­catalyzed co-cyclotrimerization of functionalized 1,7-diynes with various alkynes has been developed using RuClCp*cod and pre­ferably Grubbs second-generation catalysts

Synthesis of functionalized CF3-containing heterocycles via [2,3]-sigmatropic rearrangement and sequential catalytic carbocyclization

International audienceA new efficient access to functionalized CF3-substituted and nitrogen or sulfur-containing heterocycles has been developed directly from diazocompounds CF3C(N2)Z (Z=CO2Me, P(O)(OEt)2). The method is based on the direct selective synthesis of doubly unsaturated substrates followed by metal-mediated carbocylization. The first step has been performed by Cu(II)-catalyzed [2,3]-sigmatropic rearrangement of propargyl- or/and allyl-containing sulfur and nitrogen ylides leading to fluorinated enynes, diolefins, and especially allenynes derivatives. The second step involves their carbocyclization via ring closing metathesis and Pauson-Khand reaction

Direct Functionalization of C(sp2)–H Bond in Nonaromatic Azaheterocycles: Palladium-Catalyzed Cross-Dehydrogenative Coupling (CDC) of 2H‑Imidazole 1‑Oxides with Pyrroles and Thiophenes

The C(sp 2 )-H bond functionalization methodology was first applied to carry out the palladium-catalyzed oxidative C-H/C-H coupling reactions of 2H-imidazole 1-oxides with pyrroles and thiophenes. As a result, a number of novel 5-heteroarylated 2H-imidazole 1-oxides, which are of particular interest in the design of bioactive molecules and advanced materials, have been synthesized in yields up to 78%. The detailed H/D-exchange experiments have also been performed to elucidate some mechanistic features of this cross-dehydrogenative coupling process. Copyright © 2019 American Chemical Society.The research was financially supported by the Russian Science Foundation (Project no. 18-73-00088)