The Chromium‐Templated Carbene Benzannulation Approach to Densely Functionalized Arenes (Dötz Reaction)

Abstract

The benzannulation of readily accessible aryl-or vinylcarbene chromium complexes by alkynes provides a straightforward synthesis of densely functionalized benzenoid and fused arenes selectively labeled with a Cr(CO) 3 fragment. The reaction occurs under mild conditions, is regioselective, and tolerates a variety of functional groups both on the alkyne and on the carbene ligand. The chromium fragment undergoes a haptotropic metal migration controlled by the substitution pattern of the arene; moreover, it activates the coordinated benzene ring towards selective nucleophilic addition and aromatic substitution. Final decomplexation occurs upon ligand exchange or oxidation reactions. Chiral information imposed on either the carbene ligand or the alkyne allows for a diastereoselective benzannulation providing optically active arene-Cr(CO) 3 complexes. 8.1

2,2′-Diphosphino- and 2,2′-Diarsenotolanes and Their Fe-, Co-, and Ni-Complexes: Pnictogen-Dependent Cyclization Tendencies and Metal-Dependent Stability and Reactivity Patterns

“…Alkyne cyclotrimerizations and related cycloadditions (e.g., Wulff–Dötz-, Pauson-Khand-, or Reppe-type reactions) are highly valued transformations that are frequently employed for constructing substituted arenes and more complicated carbocyclic motifs in an atom-efficient manner . If two or more alkynes are involved in these reactions, metallacyclopentadienyl intermediates are commonly considered to play a crucial role .…”

Construction of a Functionalized Selenophene‐Allylidene Ligand via Alkyne Double Action at a Diiron Complex

“…Alkynes are versatile reagents in a multitude of valuable organic transformations, some of them being established even on an industrial scale, such as the Dötz reaction, the alkyne metathesis and the alkyne cyclotrimerization . Alkynes are prone to cyclization reactions, and in particular 1,3‐dipolar cycloadditions to various substrates provide straightforward access to a range of heterocyclic structures with possible pharmaceutical applications .…”

Synthesis and Characterization of Amphiphilic Azobenzene Sugar Chromium Carbenes

“…Our research interest is focused on the chemistry of group VI carbene complexes, which are widely applied as reagents for organic synthesis . The [3+2+1]-benzannulation reaction of aryl- or vinylcarbene chromium complexes with alkynes provides direct access to functionalized benzenoids and fused arenes selectively labeled with a Cr(CO) 3 fragment . These Cr(CO) 3 complexes are valuable reagents in asymmetric synthesis due to their planar chirality .…”