Cyaphide‐Azide 1,3‐Dipolar Cycloaddition Reactions: Scope and Applicability

Abstract

Several examples of the cyaphide‐azide 1,3‐dipolar cycloaddition reaction to afford metallo‐triazaphospholes are reported. The gold(I) triazaphospholes Au(IDipp)(CPN3R) (IDipp=1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene; R=tBu, Ad, Dipp), magnesium(II) triazaphospholes, {Mg(DippNacNac)(CPN3R)}2 (DippNacNac=CH{C(CH3)N(Dipp)}2, Dipp=2,6‐diisopropylphenyl; R=tBu, Bn), and germanium(II) triazaphosphole Ge(DippNacNac)‐(CPN3tBu) can be prepared straightforwardly, under mild conditions and in good yields, in a manner reminiscent of the classic alkyne‐azide click reaction (albeit without a catalyst). This reactivity can be extended to compounds with two azide functional groups such as 1,3‐diazidobenzene. It is shown that the resulting metallo‐triazaphospholes can be used as precursors to carbon‐functionalized species, including protio‐ and iodo‐triazaphospholes.

An Inorganic Click Reaction for the Synthesis of Interlocked Molecules

“…The 31 P NMR chemical shifts for 3a and 4a are comparable to those of other triazaphospholes. [32] Crystals of 3a suitable for single-crystal X-ray diffraction were obtained from the reaction mixture upon standing, and confirmed the formation of the [2]rotaxane (Figure 1). Remarkably, 3a required no special handling and could be isolated in moderate yields (38 %) by filtration followed by column chromatography.…”

“…[29][30][31] We have also gone on to show that inorganic click reactivity is common to a wide range of metal complexes containing a cyaphide ligand. [32] These cycloaddition reactions proceed rapidly, and in non-polar solvents, to selectively afford the metallo-triazaphospholes in high yields. We reasoned that this could offer a general route to incorporating both organometallic moieties and donor phosphorus atoms into interlocked molecules.…”