Palladium-Mediated Three-Component Synthesis of Furo[2,3-b]pyridones by One-Pot Coupling of 3-Iodopyridones, Alkynes, and Organic Halides

Abstract

[reaction: see text] The one-pot assembly of 4-alkoxy-3-iodo-2-pyridones, terminal alkynes, and organic halides has been achieved by integration of two sequential palladium-mediated cross-coupling reactions--Sonogashira and Wacker-type heteroannulation processes--and subsequent deprotection of the alkoxy group to afford furo[2,3-b]pyridones.

Intramolecular Suzuki–Miyaura Reaction for the Total Synthesis of Signal Peptidase Inhibitors, Arylomycins A2 and B2

“…[44] Although reduction of aryl iodides to arenes is a common side reaction encountered in the palladium-catalyzed process, the hydride source under the present reaction Table 1. Survey of reaction conditions [a] of palladium-catalyzed intramolecular cyclization of linear tripeptides 21 and 22.…”

“…Our approach features a key copper-catalyzed coupling reaction between a Grignard reagent and an alkyl bromide and is shown in Scheme 9. Grignard reagent, freshly prepared in situ from 1-bromo-3-methylbutane (43) and magnesium, coupled smoothly with ethyl-7-bromoheptanoate (44) in the presence of a catalytic amount of CuCl and excess of NMP [34] to afford the ethyl ester 45 in 72 % yield. This reaction, developed by Cahiez et al, [51] was highly chemoselective and could easily be performed on a multigram scale.…”

Pd‐Assisted Multicomponent Synthesis of Heterocycles

“…Remarkably, a single palladium catalyst intervenes in three different transformations in this process, acting alternatively as an organometallic reagent or as a Lewis acid (Scheme 13). [20] Scheme 13…”

Five‐Membered Heterocycles: Furan

“…Palladium-mediated sequential cross-coupling Sonogashira reaction-Wacker-type heteroannulation and deprotection reactions of pyridones, alkynes and organic halides furnish substituted furo [2,3-b]pyridones (e.g., 146) in a one-pot operation (Scheme 6.62) [115]. The coupling products of pyridones and alkynes can be separated and a single palladium catalyst intervenes in three different transformations.…”