Copper-Catalyzed Alkenylation of Cyanamides

Abstract

An efficient procedure for the copper-catalyzed cross-coupling between a broad range of cyanamides and iodoalkenes is reported. Upon reaction with catalytic amounts of copper(I) iodide and 2,2'-bisimidazole in the presence of cesium carbonate in DMF at 80 °C, a fast, regioselective, and stereoretentive cross-coupling occurs. This reaction, which was found to have a broad substrate scope, provides the first general entry to N-alkenylcyanamides, building blocks that hold great synthetic potential.

Copper-Catalyzed, Ligand-Controlled N(sp3)- or N(sp)-Selective Arylation of Cyanamides

“…2−6 Moreover, it does also confer to cyanamides the ability to act as efficient ligands for various transition metals. 7−9 In line with our interest in copper-catalyzed reactions 10,11 and transition metalcatalyzed reactions of cyanamides, 12,13 we became interested in their N-arylation and more particularly in the control over the chemoselectivity (sp-vs sp 3 -hybridized nitrogen atom) of the process.…”

“…Cyanamides are versatile building blocks containing three reactive sites: a carbon atom (sp-hybridized) and two nitrogen atoms (sp- and sp 3 -hybridized) . This dense array of electrophilic and nucleophilic positions in cyanamides provides a unique reactivity and allows a myriad of ionic, radical, pericyclic, and metal-catalyzed transformations. − Moreover, it does also confer to cyanamides the ability to act as efficient ligands for various transition metals. − In line with our interest in copper-catalyzed reactions , and transition metal-catalyzed reactions of cyanamides, , we became interested in their N-arylation and more particularly in the control over the chemoselectivity (sp- vs sp 3 -hybridized nitrogen atom) of the process.…”

Preparation of Axially Chiral 2,2′-Biimidazole Ligands through Remote Chirality Delivery and Their Application in Asymmetric Carbene Insertion into N–H of Carbazoles

“…Therefore, the design and synthesis of efficient and practical chiral imidazole ligands is highly desirable. Among the various types of imidazoles, 2,2′-biimidazoles served as the bimeric analogues of imidazole have been used as ligands applying to copper-catalyzed coupling reactions . However, the design of 2,2′-biimidazole compounds as chiral ligands has rarely been reported.…”

Synthesis and Reactivity of N-Allenyl Cyanamides

“…Considering that N -allenyl cyanamides are a novel structural motif, we next explored their derivatization with a view toward generating a variety of cyanamides that would be challenging to access using existing methods. To this end, employing the method developed by Kimber and co-workers, a variety of N -alkenyl cyanamides 17 – 20 were accessed from N -allenyl cyanamide 4 in high yields (68–93%) via intermolecular Au­(I)-catalyzed hydroarylation and hydroamination protocols (Scheme A). Furthermore, 4 participates in stereoselective [2 + 2] and [4 + 2] cycloadditions with phenylacetylene and cyclopentadiene, giving cycloadducts 21 and 22 in 75% and 64% yield, respectively (Scheme B).…”