Novel Convenient Method for the Synthesis of N,N-Bis(trimethylsilyloxy)enamines

Abstract

Both primary and secondary aliphatic nitro compounds 1 were found to react with two equivalents of bromotrimethylsilane in the presence of triethylamine followed by aqueous workup to give appropriate N,N-bis(trimethylsilyloxy)enamines 3 in good isolated yields. Products 3, starting from some secondary and/or sterically hindered compounds 1, are synthesized from the corresponding silyl nitronates 2.

Chemistry of N,N-Bis(silyloxy)enamines, Part 5

“…Results and Discussion. The other model that was suggested for the C,C-cross-coupling reactions of BENA seems to be more realistic [10] (Scheme 2). Mechanism of the Reaction of BENA with Azoles.…”

“…Possible Mechanism of Interaction of BENA 3 with C-Nucleophiles (see[10]) Study of Interaction between BENA 3 and N-Trialkylsilyl Derivatives 4. Design of Azolyl Oximes 5 from Aliphatic Nitro CompoundsScheme 2.…”

C−H Reactivity of the α‐Position in Nitrones and Nitronates

“…The N ‐hydroxyenamine tautomeric form can be fixated by silylation, as demonstrated by Torssell, Simchen and Ioffe . Thus, N ‐siloxyenamines 9 can be prepared by treatment of N ‐ tert ‐butyl‐substituted nitrones 8 with TMSCl in the presence of Et 3 N [Scheme , Eq.…”

“…Transformation of nitronates into N , N ‐bis(oxy)enamines usually requires stronger silylating agents such as trialkylsilyl bromides and triflates in the presence of a base (usually Et 3 N) . Under these conditions, both O ‐silyl nitronates 12 and cyclic O ‐alkyl nitronates 14 can be quantitatively converted into the corresponding N ‐siloxyenamines 13 and 15 (Scheme ).…”

“…The synthesis of N , N ‐bis(siloxy)enamines 13 is usually combined with the in situ generation of silyl nitronates 12 from nitroalkanes in a one‐pot process . The silylation of nitronates is characterized by high regioselectivity, producing exclusively products 13 and 15 with terminal double bonds.…”