Synthesis of Diversely Functionalized Oxindoles Enabled by Migratory Insertion of Isocyanide to a Transient σ‐Alkylpalladium(II) Complex

Abstract

Palladium‐catalyzed intramolecular carbopalladation of N‐aryl acrylamides followed by migratory insertion of an isocyanide‐coordinated C(sp3)−Pd intermediate afforded an alkylimidoyl−PdII complex, which can be intercepted by a nucleophile, including heteroarenes. In addition to amides, the alkylimidoyl−PdII complex was successfully converted into esters, ketones, and bis‐heterocyclic compounds. An unprecedented palladium‐catalyzed enantioselective domino process involving isocyanide was also documented.

Transition-metal free oxidative carbo-carboxylation of alkenes with formate in air

“…Since Overman reported the first method for asymmetric intramolecular Heck reaction using substituted acyclic (Z)-N-(2-iodophenyl)but-2-enamide as the substrate in 1998, 6 many efforts have been made to construct the oxindole-3-acetic acid derivatives through the palladium catalysed Domino-Heck reaction with different C1 sources, such as CO gas 7 or its precursors. 8 Besides, reactions utilizing CHCl 3 9 or isocyanides 10 as the C1 source under palladium catalysis were also reported. All of the above-mentioned reactions require organo ( pseudo)halide as the substrate, which is the main limitation for the synthetic application of these methods.…”

Highly regioselective and stereoselective cascade reductive cyclization of δ-ketoamide: practical access to oxa-bridged benzazepines

“…4 Among them, the cascade reductive cyclization process represents an excellent way to construct various structurally complex and valuable core skeletons. 5 Compared with the well-established one-step reductive reaction, cascade reductive cyclization is more challenging, which has to undergo two or more than two complicated cascade reductive processes and avoid any intermediates from being quenched until generating the desired products. In most cases, an activated hydride donor (from reducing reagents, such as aluminum lithium reagent; boron reagent) and a hydride acceptor (such as aldehyde; ester; amide) are necessary for the cascade reductive cyclization.…”