Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

Abstract

SummaryPalladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene derivatives using alcohol nucleophiles were investigated. The optimal conditions were found to be 10 mol % PdCl2(CH3CN)2 in methanol, offering yields up to 92%. The reaction was successful using primary, secondary and tertiary alcohol nucleophiles and was compatible with a variety of substituents on cyclopropanated oxabenzonorbornadiene. With unsymmetrical C1-substituted cyclopropanated 7-oxabenzonorbornadienes, the regioselectivity of the reaction was excellent, forming only one regioisomer in all cases.

Ruthenium-Catalyzed Oxidative Cross-Coupling Reaction of Activated Olefins with Vinyl Boronates for the Synthesis of (E,E)-1,3-Dienes

“…Interestingly, cyclopropyl vinyl boronate ester 1k furnished dienes 3kb and 3kc in 78 and 75% yields, respectively, without affecting its highly strained cyclopropyl ring. It is important to highlight that the coupling reaction of highly strained cyclopropane ring derivatives is likely to undergo ring cleavage under a palladium catalytic system . Also, electron-withdrawing acetoxy-substituted vinyl boronate ester 1l reacted with n -butyl acrylate ( 2b ) to generate functionalized diene 3lb in 82% yield.…”

Intramolecular Palladium-Catalyzed Ring Opening of Oxabenzonorbornadienes with C1-Tethered Aryl Halides

“…In addition to this, it may be interesting to observe if the reaction proceeds with the cyclopropanated derivative of OBD. Although the molecule lacks an alkene moiety, the cyclopropane has been reported to undergo similar modes of ring opening. , …”