The Cyanamide Moiety, Synthesis and Reactivity

Abstract

The cyanamide moiety provides many opportunities as a building block for the synthesis of nitrogen-containing heterocycles. This review discusses the reported methods for the preparation of alkyl-and N-acylcyanamides and illustrates their reactivity visà-vis nucleophilic additions, cycloadditions, radical chemistry and coordination chemistry. 1 Introduction 2 Biological Relevance of the Cyanamide Moiety 3 Access to Cyanamides 3.1 Cyanation of Amines 3.2 Palladium Catalysis 3.3 Deoxygenation of Isocyanates 3.4 Desulfurization of Thioureas 4 Reactivity of Cyanamides 4.1 Nucleophilic Additions 4.2 Cycloadditions 4.3 Additions to Carbonyl Groups 4.4 Chlorinations and Oxidations with tert-Butyl-N-chlorocyanamide 4.5 Cyanamides as Radical Partners 5 Coordination Chemistry of Cyanamides 6 Conclusion

Structure and Additive-free Transamidation of Planar N-Cyano Amides

“…1 H-NMR (300 MHz, CDCl 3 ) δ: 7.24−7.36 (m, 5H), 5.67 (brs, 1H), 5.11 (td, J = 6.8, 15.1 Hz, 1H), 1.97 (s, 3H), 1.47 (d, J = 6.8 Hz, 3H). 13 (14), 120 (34), 106 (100), 105 (16), 104 (22), 77 (13). HRMS (EI) m/z: [M] + Calcd for C 10 H 13 NO 163.0092; found 163.0094.…”

“…1 H-NMR (300 MHz, CDCl 3 ) δ: 5.41 (brs, 1H), 3.17−3.24 (td, J = 7.1, 6.3 Hz, 2H), 1.95 (s, 3H), 1.41−1.49 (br, 2H), 1.28 (br, 10H), 0.86 (t, J = 6.7, 5.9 Hz, 3H). 13 (20), 142 (17), 128 (17), 114 (35), 101 (14), 100 (48), 87 (21), 79 (98), 72 (100), 60 (34), 55 (13), 44 (22), 43 (37), 41 (10) Synthesis of 13b. To a solution of 4 (174 mg, 1.00 mmol) in CH 3 CN (1 mL) in a round flask (10 mL) equipped with a stirring bar was added allylamine (150 μL, 2.00 mmol) in one shot, and the mixture was stirred for 25 h under an Ar atmosphere at 30 °C.…”

“…24 In addition, the structure and reactivity of N-cyano amide are of interest since the reaction of an N-cyano compound with a nucleophile at the cyano carbon has been reported. 34 Herein, we describe the structures and trans amidation reaction of N-cyano amides. We found that Ncyano amides are a prominent substrate for transamidation.…”

“…We hypothesize that the linear geometry of the cyano group would expand the substrate scope and bypass the need for the harsh reaction conditions employed in the literature . In addition, the structure and reactivity of N -cyano amide are of interest since the reaction of an N -cyano compound with a nucleophile at the cyano carbon has been reported . Herein, we describe the structures and trans amidation reaction of N -cyano amides.…”

3-Dialkylamino-1,2,4-triazoles via ZnII-Catalyzed Acyl Hydrazide–Dialkylcyanamide Coupling

“…In view of our general interest in reactions of metal-activated substrates featuring CN triple bonds (for our reviews see refs and ) and, in particular, synthetic approaches allowing facile transformations of rather unreactive cyanamides (reviews; , recent studies, see refs − ), we decided to study a possibility of Zn II -catalyzed synthesis of 3-NAlk 2 -1,2,4-triazoles from acyl hydrazides and dialkylcyanamides. Usage of zinc­(II), apart from the low cost and rather environmentally friendly character of this metal center, was additionally stimulated by its recent applications in advanced organic synthesis − and by our own studies disclosing a detailed mechanism of Zn II /H + -mediated generation of 5-amino-1,2,4-oxadiazoles via amidoxime–cyanamide coupling …”