Chemoselective C−H Bond Activation: Ligand and Solvent Free Iron-Catalyzed Oxidative C−C Cross-Coupling of Tertiary Amines with Terminal Alkynes. Reaction Scope and Mechanism

Abstract

FeCl 2 catalyzes the oxidative C-C cross-coupling of tertiary amines with terminal alkynes into propargylamines using (t-BuO) 2 as oxidant. The reaction can be applied to aromatic and aliphatic amines and alkynes without solvent. High chemoselectivity for aminomethyl groups is due to a steric factor.

PEGylated magnetic nanoparticles (PEG@Fe 3 O 4 ) as cost effective alternative for oxidative cyanation of tertiary amines via C H activation

“…In this regard, transition-metal-catalyzed C H bond activation, particularly of unactivated sp 3 C H bonds, has emerged to be a promising but highly challenging approach in organic synthesis [12][13][14][15]. Recently, the direct oxidative cyanation of C H bonds in tertiary amines to give corresponding ␣-aminonitriles has attracted much interest as these compounds are highly useful and versatile intermediates which find extensive applications in a wide range of natural products and nitrogen containing bioactive compounds such as alkaloids [16][17][18][19]. Further, these bi-functional organic compounds having adjacent functional groups show dual reactivity as the nucleophilic addition provides an easy access to various compounds such as ␣-amino aldehydes, ketones and ␤-amino alcohols [20][21][22][23][24][25].…”

Iron-Catalyzed Cross-Dehydrogenative-Coupling Reactions

“…In 2009, Volla and Vogel reported iron-catalyzed CDC reactions of tertiary amines and terminal alkynes to give propargylamines (Scheme 32) [58]. Screening reactions revealed that FeCl 2 without solvent in air was the best catalyst.…”

Iron Catalysis in Synthetic Chemistry

“…Instead of 1,3-dicarbonyl systems, an α-sp 3 C-H bond from nitrogen was found effective in CDC with terminal alkynes (Scheme 79) (99).…”