Dual Gold‐Catalyzed Cycloaromatization of Unconjugated (E)‐Enediynes

A synthesis of unconjugated (E)‐enediynes from allenyl amino alcohols is reported and their gold‐catalyzed cascade cycloaromatization to a broad range of enantioenriched substituted isoindolinones has been developed. Experimental and computational studies support the reaction proceeding via a dual‐gold σ,π‐activation mode, involving a key gold‐vinylidene‐ and allenyl‐gold‐containing intermediate.     

Photochemical Rearrangements of 6-Methoxymethylbicyclo[4.4.0]Dec-1-En-3-One and 6-Methoxymethylbicyclo[4.3.0]Non-1-En-3-One

The irradiation of the title compounds 6 and 12 in isooctane and benzene was investigated. The photochemical reactions took place sluggishly upon n→π^* excitation (λ > 300 nm) in deoxygenated solutions but more rapidly in the presence of air; deconjugation to yield β,γ-unsaturated ketones and lumiketone rearrangement were the main primary photochemical reactions. In contrast, intramolecular hydrogen abstraction by the C_α-carbon was the main reaction upon π→^* excitation (λ = 254 nm).     

A General Method for Synthesizing 3-Methyl Cyclopent-2-En-1-Ones

During the investigation on the mechanism of the rearrangement reaction of the dihydroindenone derivatives (1 and 2)¹⁾, we need to prepare β-methyl derivative such as 1m.