N‐Oxide as a Traceless Oxidizing Directing Group: Mild Rhodium(III)‐Catalyzed CH Olefination for the Synthesis of ortho‐Alkenylated Tertiary Anilines

Abstract

Double role: A traceless directing group also acts as an internal oxidant in a novel Rh(III) -catalyzed protocol developed for the synthesis of ortho-alkenylated tertiary anilines. A five-membered cyclometalated Rh(III) complex is proposed as a plausible intermediate and confirmed by X-ray crystallographic analysis.

Fluorine Effects on Group Migration via a Rhodium(V) Nitrenoid Intermediate

“…[6] As an important class of structural motifs that have found widespread use in synthetic chemistry, ortho-alkenylated aniline derivatives and their preparation have attracted considerable attention from organic chemists. [8][9][10][11] Although synthetically enabling, prominent limitations of these protocols remain, such as the requirement of substrate prefunctionalization, as toi-chiometric amount of external oxidants,and/or harsh reaction conditions.Therefore,the development of novel and efficient synthetic protocols that provide straightforward access to these structural motifs is still highly desirable.H erein, we report ahydroarylation reaction of internal alkynes involving as keletal rearrangement induced by fluorine effects,ascenario that not only nicely fulfills these synthetic demands but more importantly elicits an unprecedented reactivity divergence engendered by the fluorine substituent. [8][9][10][11] Although synthetically enabling, prominent limitations of these protocols remain, such as the requirement of substrate prefunctionalization, as toi-chiometric amount of external oxidants,and/or harsh reaction conditions.Therefore,the development of novel and efficient synthetic protocols that provide straightforward access to these structural motifs is still highly desirable.H erein, we report ahydroarylation reaction of internal alkynes involving as keletal rearrangement induced by fluorine effects,ascenario that not only nicely fulfills these synthetic demands but more importantly elicits an unprecedented reactivity divergence engendered by the fluorine substituent.…”

Fluorine Effects on Group Migration via a Rhodium(V) Nitrenoid Intermediate

“…[7] Thew ellknown Suzuki and Mizoroki-Heck coupling reactions,t he Fujiwara-Moritani reaction, directing-group assisted dehydrogenative coupling, and the hydroarylation of alkynes are the main current strategies. [8][9][10][11] Although synthetically enabling, prominent limitations of these protocols remain, such as the requirement of substrate prefunctionalization, as toi-chiometric amount of external oxidants,and/or harsh reaction conditions.Therefore,the development of novel and efficient synthetic protocols that provide straightforward access to these structural motifs is still highly desirable.H erein, we report ahydroarylation reaction of internal alkynes involving as keletal rearrangement induced by fluorine effects,ascenario that not only nicely fulfills these synthetic demands but more importantly elicits an unprecedented reactivity divergence engendered by the fluorine substituent.…”

Rhodium‐Catalyzed C(sp2)‐ or C(sp3)−H Bond Functionalization Assisted by Removable Directing Groups

“…Theuse of an N-oxide as atraceless oxidizing directing group in the Rh-catalyzed ortho-alkenylation of tertiary amines was reported. [242] Theo xidizing properties of the Noxide moiety eliminate or reduce the need for an external oxidant. Arepresentative example of the reduction of the Noxide 206 using trichlorophosphine to afford the corresponding reduction product 207 is shown in Scheme 65.…”