Electrophilic Trapping of Semibenzenes

Abstract

In this work, we demonstrate how allylative dearomatization of benzyl chlorides can provide direct access to a variety of semibenzenes. These scaffolds behave as highly reactive nucleophiles in the presence of carbocations. In addition, semibenzenes are susceptible to intramolecular rearrangements rendering a broad scope of functionalized arenes. An analysis of this new reactivity is reported, as well as the rationale behind the observed intramolecular reorganizations.

Ligand‐free MnBr2‐Catalyzed Chemo‐ and Stereoselective Hydroboration of Terminal Alkynes

“…[22] This suggest that the reaction might proceed via a radical process. To know the participation of Mnhydride intermediate, the standard reaction was performed in the presence of tritylium tetrafluoroborate (hydride abstract reagent), [23] wherein the product formation was not observed. This finding suggests the involvement of a manganese-hydride intermediate.…”

One-pot synthesis of multisubstituted propenylbenzenes from benzyl chlorides through relay catalysis of palladium

“…After the report of the allylative dearomatization of benzyl chlorides with allyltributylstannane in 2001 (Scheme 1a), 11 allylative dearomatization has been regarded as an effective method to introduce allyl groups into aromatic rings. 12 In the course of our continuous research on the selective transformation of benzyl chlorides via π-benzyl palladium intermediates, 13 we achieved here the meta -C–H bond propenylation of benzyl chlorides via a one-pot sequential allylative dearomatization/Wagner–Meerwein rearrangement/olefin isomerization procedure to produce multisubstituted propenylbenzenes with high regioselectivity. In this transformation, the Cope-type rearrangement product, namely the ortho -C–H bond propenylation product, was not generated (Scheme 1b).…”