A Convenient Synthesis of 1, 2, 4‐ and 1, 3, 4‐Azadiphospholes. Issue 42 (31st August 2016)

• Record Type: Journal Article
• Authors: Suter, Riccardo; Benkő, Zoltán; Grützmacher, Hansjörg
• Is Part Of: Chemistry. Volume 22:Issue 42(2016)
• Page Start: 14979
• Page End: 14987
• Publication Date: 2016-08-31
• Subjects: azadiphosphole -- cycloaddition -- heterocycles -- phosphaethynolate -- reaction mechanisms; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201602864
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A new synthetic route to functionalized neutral and anionic azadiphospholes from easily accessible starting materials is described. Equimolar reaction of Na(OCP) and N ‐(2, 6‐dimethylphenyl)pivalimidoyl chloride2 a cleanly affords the imidoxy‐functionalized 1, 2, 4‐azadiphosphole3 a . Using Na(OCP) and imidoyl chloride in a 2:1 ratio leads to an anionic four‐membered ring Na[4 a ], which has been structurally characterized. During 16 h at room temperature, Na[4 a ] rearranges to the anionic 1, 3, 4‐azadiphospholide Na[5 a ] with release of carbon monoxide. Applying the more sterically demanding N ‐(2, 6‐diisopropylphenyl)pivalimidoyl chloride allows isolation of the 1, 3, 4‐azadiphospholide Na[5 b ] in good yield (>70 %). Possible mechanisms leading to the new isomeric azadiphospholides have been investigated with the aid of high‐level composite calculations. Abstract : Atom efficient on a preparative scale : A convenient synthetic route to functionalized neutral and anionic 1, 2, 4‐ and 1, 3, 4‐azadiphospholes from sodium phosphaethnyolate [Na(OCP)] and imidoyl chloride (IMCl) has been developed. The reaction proceeds via the formation of an anionic four‐membered ring intermediate (see graphic; counter cations are not shown in the scheme.)