Enantioselective Difunctionalization of Alkenes by a Palladium‐Catalyzed Heck/Sonogashira Sequence

Abstract

Sonogashira‐type cross‐couplings are one of the most significant alkynylations in organic chemistry. One of the first palladium‐catalyzed intramolecular Heck/Sonogashira reactions of alkenes with terminal alkynes is now reported. With this method, a variety of uniquely substituted chiral benzene‐fused heterocycles bearing a propargyl‐substituted all‐carbon quaternary stereocenter were obtained in a straightforward, high‐yielding, and highly stereoselective manner under mild conditions. Salient features of this process include the use of readily available substrates, high selectivities, a broad substrate scope as well as versatile product functionalizations.

Palladium-Catalyzed Asymmetric Domino Heck/Carbocyclization/Suzuki Reaction: A Dearomatization of Nonactivated Naphthalenes

“…Heck-Sonogashira reaction, [30][31][32] Heck-Suzuki reaction, 33,34 and Heck carbonylative reaction, [35][36][37][38] have been developed for the synthesis of valuable structures (Scheme 1a). Alternatively, by switching the crosscoupling of alkyl-PdX to reductive elimination, intriguing reductive Heck and Heck carboiodination reactions have been reported (Scheme 1a).…”

Nickel-Catalyzed Reductive Asymmetric Aryl-Acylation and Aryl-Carbamoylation of Unactivated Alkenes

“…[1][2][3][4][5][6] The majority of these reactions relies on a facially selective Heck-type arylmetallation of the pendant olefinic unit as the enantiodetermining step, 7 which is followed by trapping of the generated σ-alkylmetal species with either a nucleophile or an electrophile. Based on this strategy, asymmetric aryl-alkylation, [8][9][10] diarylation, [10][11][12][13] arylbenzylation, 14 aryl-alkenylation 15,16 and aryl-alkynylation 13,17,18 of incorporated alkenes have been developed under palladium, copper or nickel catalysis.…”

Palladium-Catalyzed Asymmetric Domino Heck/Carbocyclization/Suzuki Reaction: A Dearomatization of Nonactivated Naphthalenes

“…Palladium-catalyzed asymmetric domino Heck reaction is one of the most powerful methods for the construction of quaternary stereocenters. 26,27 Through trapping of the in situ generated alkyl-PdX intermediate, various enantioselective domino reactions, including Heck tandem coupling with azoles, 28,29 (dearomative) Heck-Sonogashira reaction, [30][31][32] Heck-Suzuki reaction, 33,34 and Heck-carbonylative reaction [35][36][37][38] have been developed for the synthesis of valuable structures (Scheme 1A). Alternatively, by switching the cross-coupling of alkyl-PdX to reductive elimination, intriguing reductive Heck and Heck carboiodination reactions have been reported (Scheme 1A).…”