Generation and Reactions of a Benzodehydrotropylium Ion–Co₂(CO)₆ Complex

Abstract

A series of 7-methylenedehydrobenzo[7]annulen-5-ol hexacarbonyldicobalt complexes were generated by Hosomi–Sakurai reactions of allylsilanes containing o-alkynylarylaldehyde-Co2(CO)6 complexes. One of the cyclization products was converted into its corresponding dihydrobenzo[7]annulen-7-ol hexacarbonyldicobalt complex, an immediate precursor to a benzodehydrotropylium–Co2(CO)6. The cation was generated in situ and reacted with four nucleophiles, and its aromatic stabilization was determined by computational methods.

Tropylium Ion, an Intriguing Moiety in Organic Chemistry

“…It was reported that the generation, trapping, and evaluation of a dehydrotropylium ion resulted in a reduced level of aromatic stabilization. The Jones group produced η 2platinum (0), palladium(0), and zirconium(II) complexes of a dehydrotropylium ion or similar cations that exhibit no to moderate C−C bond alternation (Figure 6) [54]. For a moderate Swern-type oxidation of a range of alcohols (8b), a novel dimethyl sulfoxide activation technique using 1,1-dichlorocycloheptatriene (8a) has been devised (Figure 7).…”

“…It was reported that the generation, trapping, and evaluation of a dehydrotropylium ion resulted in a reduced level of aromatic stabilization. The Jones group produced η 2 -platinum (0), palladium(0), and zirconium(II) complexes of a dehydrotropylium ion or similar cations that exhibit no to moderate C−C bond alternation ( Figure 6 ) [ 54 ].…”