Novel Alkylation-Annulation Reaction of Fischer Carbene Complexes

Di- and Polymetallic Heteroatom Stabilized (Fischer) Metal Carbene Complexes

“…Thus, compounds 302 are deprotonated, and the resulting anions 305 experiments an intramolecular addition reaction to the remaining carbene carbon to form 306 . This intermediate losses the metallic moiety to form 304 after a 1,3-hydrogen shift (Scheme ) 60 …”

Transformation of a Pyrazolidene into a Tetrahydropyrimidinylidene Ligand by Deprotonation/Reprotonation

“…A few tungsten complexes have been synthesized by reaction of aminocarbene complexes with dichloromethane or dibromomethane under phase transfer conditions [6] or by cycloaddition of urea with alkynyl(alkoxy)carbene complexes [7]. The formation of a tetrahydropyrimidinylidene ligand by ring enlargement of a pyrazolidene ligand is, to the best of our knowledge, without precedence.…”

The [5+5] route to the phenanthrene skeleton

“…A variety of γ,δ-carbene complexes can arise through allylation of carbene complexes having α-hydrogens. 22 These derivatives are also accessible from γ,δ-unsaturated acid chlorides (themselves the products of Claisen rearrangements) through the Hegedus 23 /Semmelhack 24 protocol, from 5-halo-1-pentene derivatives through lithiation followed by the Fischer synthesis, or from Michael addition of vinyl anion equivalents to α,β-unsaturated carbene complexes. 25 The o -alkynylbenzoyl coupling partners arise from 2-halobenzaldehydes or salicaldehyde derivatives through Sonogashira couplings, or through acylation of o -alkynylphenyl halide derivatives.…”