Bis f-butyldimethylsilyl hydrazine

Bonnet-Delpon, D. Lequeux, T., Tetrahedron Lett. 1993, 34, 3279. 

Preparative Methods prepared by reacting f-butyldimethylchlo-rosilane with anhydrous hydrazine at 70 °C (eq 1), with or without solvent. 

Handling, Storage, and Precaution this reagent should be viewed as a latent source of hydrazine all safety precautions relating to the handling of hydrazine should he considered applicable to this reagent. 

Reaction with Aldehydes and Ketones. Classical preparations of aryl and alkyl hydrazones with hydrazine lead to mixtures of hydrazones and azines (eq 2). 

This problem can be surmounted by the use of BTBSH, which affords the (V-silyl hydrazones cleanly and in high yield (eq 3). Thus, iV-silylated aryl and alkyl hydrazones are prepared hy reaction of l,2-bis(t-butyldimethylsilyl)hydrazine with an aldehyde or ketone in the presence of a catalytic amount of Sc(OTf)3 in dichloromethane (eq 3). A number of Lewis acid catalysts were explored, with Sc(OTf)3 being the most effective, giving the hydrazones in yields of up to 95% as mixtures of the syn- and anti-isomers. In the absence of Lewis acid catalysis, the reaction does not proceed. Unlike the simple hydrazine-derived hydrazones, the resulting iV-silyl hydrazones are stable, isolable, and capable of being stored for extended periods of time. 

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The monolithiated bis(fe/-f-butyldimethylsilyl)hydrazine 47 is obtained in the reaction of the A, A -bis(ferf-butyldimethylsilyl)hydrazine with -BuLi in thf in a molar ratio 1 1. 

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