Palladium-Catalyzed Intermolecular Azidocarbonylation of Alkenes via a Cooperative Strategy

Abstract

A novel intermolecular β-azidocarbonylation reaction of alkenes has been developed in which a combination of iodine(III)-mediated alkene activation and palladium-catalyzed carbonylation was demonstrated as an efficient strategy for the difunctionalization of alkenes. A variety of β-azido carboxylic esters were obtained from mono- and 1,1-disubstituted terminal alkenes with excellent regioselectivities. In addition, the introduced azido group can be reduced to an amine group, providing a facile access to β-amino acid derivatives from simple olefins.

The Chemistry of CO: Carbonylation

“…Liu and co-workers developed several novel procedures for the oxidative carbonylative transformation of alkenes (Scheme 7). [26][27][28] With palladium as the catalyst and hypervalent iodine as a promoter, both terminal and internal alkenes can be effectively transformed under mild reaction conditions. From the point of view of reaction mechanisms, a three-membered iodonium ion intermediate is initially formed after an alkene reacts with hypervalent iodine.…”

Palladium-catalyzed intermolecular alkynylcarbonylation of unactivated alkenes: easy access to β-alkynylcarboxylic esters

“…Through our continuous interest in palladium-catalyzed intermolecular difunctionalization of alkenes, 12 we have developed several oxidative carbonylations of unactivated alkenes in the presence of hypervalent iodine reagents, including amino-, oxy-, azido- and fluorocarbonylation. 13 Meanwhile, we have also demonstrated a palladium-catalyzed arylcarbonylation of unactivated alkenes with diaryliodonium salts as arylation reagents, which involved an aryl–Pd II species generated through oxidation of Pd(0) by diaryliodonium salts. 14 Inspired by this study, we envisioned that, if EBX reagents were used instead of diaryliodonium salts to generate an alkynyl–Pd( ii ) intermediate, the alkynylcarbonylation reaction might be accessible to afford β-alkynylcarbonyl compounds.…”

Palladium-Catalyzed Intermolecular Carbonylation-Based Difunctionalization of Alkenes

“…With the same cooperative strategy, an azido-based hypervalent iodine reagent (Zhdankin reagent) was applied to the intermolecular -azidocarbonylation of alkenes, yielding -azido acid derivatives. 16 Notably, similar to previous oxycarbonylation and fluorocarbonylation, BF 3 •OEt 2 as a Lewis acid is also required to activate N 3 reagent, which facilitates alkene activation to form a three-membered iodonium ion intermediate. A variety of alkenes such as mono-and 1,1-disubstituted terminal alkenes, styrenes, and internal alkenes were successfully transformed to -azido carbonyl compounds with excellent regioselectivity (Scheme 9).…”