Tandem Catalysis: Rh(III)-Catalyzed C–H Allylation/Pd(II)-Catalyzed N-Allylation Toward the Synthesis of Vinyl-Substituted N-Heterocycles

Abstract

Tandem catalysis by Rh(III)/Pd(II) was realized, enabling rapid access to two important N-heterocycles that bear a synthetically valuable vinyl substituent. The reaction occurred under mild reaction conditions and was easy to handle. Good substrate scope and high regioand stereoselectivities were observed. The vinyl group was demonstrated to be a reliable handle for functional group interconversions. The alkene effect was found to be the key factor for the success of this process.

Polycyclization Enabled by Relay Catalysis: One‐Pot Manganese‐Catalyzed C−H Allylation and Silver‐Catalyzed Povarov Reaction

“…We have been interested in combining CÀHa ctivation and catalystr elay strategy for high efficient multi-bondf orming reactions. [8] The aza Diels-Alder reaction between an aromatic imine and an alkene, also known as the Povarov cycloaddition, is aw ell-known process targeted for tetrahydroquinoline synthesis. [9] We envisionedt hat the imine group, prior to its involvement in the [4+ +2] cycloaddition reaction, couldp otentially act as ad irectingg roup to enablet he introduction of ap endent alkene, thereby enabling aL ewis acid-catalyzed intramolecular Povarov cycloaddition (Scheme 1a).…”

Cobalt‐Catalyzed Annulation Reactions via C−H Bond Activation

“…Then, Ackermann described the first cascade C−H/N‐H allylation of imidates 49 with 4‐vinyl‐1,3‐dioxolan‐2‐one 51 to access vinylated isoquinolines 52 (Scheme ) . Unlike the previous Rh‐catalyzed reactions which afforded only ortho C−H allylation products in the presence of Rh III complex, whereas Rh III /Pd II dual catalysis provided the cyclized vinyl isoquinoline derivatives . Gratifyingly, in this case, CoCp* catalyst itself facilitates both o ‐allylation and cyclization step and does not require any additional metals such as palladium for further cyclization.…”

Comparison of the Reactivities and Selectivities of Group 9 [Cp*MIII] Catalysts in C−H Functionalization Reactions

“…[22] The authors hypothesized that a[ Cp*Rh III ]s pecies mediated the CÀHa llylationo fa nN-methoxybenzamide on reaction with a4 -vinyl-1,3-dioxolan-2-one as an olefin source to form an allylated intermediate that subsequently underwent N-allylic alkylation under Pd II catalysis to afford the final product. [22] The authors hypothesized that a[ Cp*Rh III ]s pecies mediated the CÀHa llylationo fa nN-methoxybenzamide on reaction with a4 -vinyl-1,3-dioxolan-2-one as an olefin source to form an allylated intermediate that subsequently underwent N-allylic alkylation under Pd II catalysis to afford the final product.…”

“…Wang and co-workers reported ao ne-pot synthesis of 3,4-dihydroisoquinolin-1(2H)-ones by using tandemR h III /Pd II catalysis (Scheme 13). [22] The authors hypothesized that a[ Cp*Rh III ]s pecies mediated the CÀHa llylationo fa nN-methoxybenzamide on reaction with a4 -vinyl-1,3-dioxolan-2-one as an olefin source to form an allylated intermediate that subsequently underwent N-allylic alkylation under Pd II catalysis to afford the final product. Interestingly,t his tandemc atalytic system gave 5,6-dihydropyridin-2(1H)-ones and 3,4-dihydroisoquinolin-…”