One‐Pot Catalytic Synthesis of gem‐Diazides and Their Direct Conversion into Safe Materials

Abstract

Commercial availability and storage issues have left reactivity studies of gem‐diazides underdeveloped, in contrast to the relatively abundant chemistry of monoazides. The present study uses triflic acid (0.1 mol‐%) as a catalyst for the quantitative production of gem‐diazides from the reaction of aldehydes with trimethylsilyl azide. The diazides could be isolated in high yields by simple evaporation of the Me3Si–O–SiMe3 byproduct. In a one‐pot synthesis, the diazide was directly treated with an N‐heterocyclic carbene to obtain a gem‐bis(triazabutadiene). Reaction of the diazide with triphenylphosphane followed by triflic acid yielded n N,N′‐bis(triphenylphosphane) adduct.

Reactions with Geminal Diazides: Long Known, Full of Surprises, and New Opportunities

“…Due to there being a range of available methods, geminal diazides derived from aldehydes are broadly accessible. [81][82][83] While studies on the reactivity of such diazides are still rare, a few interesting reactions with diazides derived from ,-unsaturated aldehydes were recently disclosed. As summarized in Scheme 41, the diazide 83 behaves mostly like a synthetic equivalent of a N,N-acetal: Single and double substitution is possible, as is elimination to imines and oxidation to nitriles.…”

“…Roesky and co-workers recently showed that the triazene formation with carbenes was also possible with geminal diazides, as exemplified in Scheme 46 . 81…”

Selective synthesis and reactivity expansion of α,β-unsaturated geminal diazides

“…[16][17][18][19][20][21] Ketals and aldehydes could also be converted into geminal diazides with Lewis acids, such as SnCl 4 , SnCl 2 , AlCl 3 , TiCl 4 and ZnCl 2 , or the strong acid TfOH as the catalyst and trimethylsilyl azide or sodium azide as the azide source (Scheme 1c). [22][23][24] As far as we know, the α,β-unsaturated aldehyde scaffold is a valuable building block. In the presence of azide negative ions, the Schmidt rearrangement products due to the loss of nitrogen (N 2 ) from the azido group (Scheme 2a) or the thermodynamically driven allylic rearrangement products (Scheme 2b) can be favorably obtained, rather than α,β-unsaturated gem-diazides.…”

“…16–21 Ketals and aldehydes could also be converted into geminal diazides with Lewis acids, such as SnCl 4 , SnCl 2 , AlCl 3 , TiCl 4 and ZnCl 2 , or the strong acid TfOH as the catalyst and trimethylsilyl azide or sodium azide as the azide source (Scheme 1c). 22–24…”

Reactivity of Organic Geminal Diazides at Tetrahedral Carbons

“…However, in light of the recent developments regarding their safe and broad synthesis, studies on the reactivity of diazidated organic compounds became easier, and a range of new reactivities were unveiled. [ 35 ] We now summarize advances in the field of diazide reactivities, with a focus on our own research program: numerous ways to provide heterocycles will be discussed; the ability to serve as an acylation reagent when treated with nucleophiles will be shown.…”