Synthesis of Unusual Oxime Ethers by Reaction of Tetranitromethane with B‐Alkylcatecholboranes

Abstract

The reaction of tetranitromethane with B-alkylcatecholboranes leads to the formation of unusual dinitrooxime ethers. A tentative mechanism is provided, which suggests the involvement of extremely fast addition of alkyl radicals to tetranitromethane. The substitution of one of the nitro groups in the oxime ethers by nucleophiles (such as secondary amines, halogens and styrene) and by radicals generated from B-alkylcatecholboranes is reported.

Highly Efficient One‐Step Synthesis of N‐Trimethylsiloxy Alkyl Imidothioates

“…Since then, we have become interested in the use of compounds that contain a silicon–sulfur bond for organic synthesis and sought a convenient method for the preparation of this class of compounds. Kim and Kadam have reported a highly efficient catalyst‐free pathway for the silylation of an OH bond by using HMDS in nitromethane . Interestingly, compounds that contain an SH bond were not previously tested in this synthetic route.…”

“…Nitroalkanes are an important class of compounds and characterized by their versatile reactivity. Unfortunately, only few examples are known for the use of nitro compounds to obtain oximes and their analogues (Figure ) …”

Reaction mechanisms: radical and radical ion reactions

“…46 Renaud et al studied the radical addition to tetranitromethane, using alkylcatecholboranes as radical precursor. 47 This sequence proceeds through an intermediate nitroxyl radical 84, which is trapped by catecholborane. In a subsequent step, elimination occurs through an ionic pathway, to give dinitrooxime ethers.…”