Synthesis, Properties, and Crystal Structure of DDQ-Adducts of Ethynylated 2H-Cyclohepta[b]furan-2-ones

Abstract

-Ethynylated 2H-cyclohepta [b]furan-2-ones reacted with 2,3-dichrolo-5,6-dicyano-1,4-benzoquinone (DDQ) in a formal [2+2] cycloaddition reaction to afford the corresponding DDQ-adducts in good yields.The electronic properties of the DDQ-adducts were investigated by UV/Vis spectroscopy. One of the DDQ-adducts was revealed the molecular structure by X-ray crystallographic analysis. The redox behavior of the new compounds was examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV).

Azulene‐Based Donor–Acceptor Systems: Synthesis, Optical, and Electrochemical Properties

“…Thus, we investigated the preparation of new TCBDs based on CHFs for the construction of multistage redox activec hromophores. The alkynes also reactedw ith TCNQ [58] and DDQ [59] to afford the corresponding addition products. Similar to TCBD derivatives with azulenyl substituents, CHF-substituted TCBDs 47-53 were obtained by the [2+ +2] CA-RE of the correspondinga lkynes with TCNE ( Figure 9).…”

“…Similar to TCBD derivatives with azulenyl substituents, CHF-substituted TCBDs 47-53 were obtained by the [2+ +2] CA-RE of the correspondinga lkynes with TCNE ( Figure 9). The alkynes also reactedw ith TCNQ [58] and DDQ [59] to afford the corresponding addition products. The CHF substituent on the alkyne acts as an activating group to promote the [2+ +2] CA-RE reaction, similar to 1-azulenyl groups.…”

The [2+2] Cycloaddition‐Retroelectrocyclization (CA‐RE) Click Reaction: Facile Access to Molecular and Polymeric Push‐Pull Chromophores

“…[c] Reaction with 4,4'-(ethyne-1,2-diyl)bis(N,N-dimethylaniline) (11). [43] 2,3,5,6-Tetrahalo-1,4-quinones afforded different types of final products.T etrafluoroquinone 20 reacted with two equivalents of 15 upon heating in 1,2-dichloroethane to afford (AE)-21 in 20 %yield. substituted spiro derivative (AE)-19 in 16 %upon heating.…”

“…[42] Theh omoconjugated push-pull chromophores obtained by the [2+ +2] CA reaction as well as the subsequently formed spiro compounds showed ICT bands in the visible range and high third-order nonlinear optical (NLO) properties.T he same reactions were reported for the alkynes substituted by p-N,N-dihexylaniline,f errocene,a nd 2Hcyclohepta [b]furan-2-one donors. [43] 2,3,5,6-Tetrahalo-1,4-quinones afforded different types of final products.T etrafluoroquinone 20 reacted with two equivalents of 15 upon heating in 1,2-dichloroethane to afford (AE)-21 in 20 %yield. [44] Thefirst reaction in ac ascade of reactions is the [2+ +2] CA,s imilar to that of DDQ.I nc ontrast, chloranil (22)…”

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

“…In particular, a [2 + 2] CA adduct was prepared through the [2 + 2] CA-RE reaction. Studies have shown that the thermal treatment of the [2 + 2] CA adduct leads to the formation of a spiro compound [89][90][91][92][93][94]. Ester-substituted, electron-deficient alkenes have also been employed in [2 + 2] CA-RE reactions involving electron-rich alkynes.…”