Double N–H bond activation of N,N′-bis-substituted hydrazines with stable N-heterocyclic silylene

Ramachandran Azhakar,Rajendra S Ghadwal,Dietmar Stalke,Herbert W Roesky,Jakob Hey

doi:10.1039/c1dt11708d

Ramachandran Azhakar, Rajendra S Ghadwal + Show 3 more

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https://doi.org/10.1039/c1dt11708d

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Journal: Dalton Trans.	Publication Date: Jan 1, 2012
Citations: 21	License type: cc-by

Affiliation: University of Göttingen

Abstract

The reaction of N-heterocyclic silylene (NHSi) L [L = CH{(C[double bond, length as m-dash]CH(2))(CMe)(2,6-iPr(2)C(6)H(3)N)(2)}Si] with benzoylhydrazine, 1,2-dicarbethoxyhydrazine, 1,2-diacetylhydrazine and 1,2-bis(tert-butoxycarbonyl)hydrazine in 1 : 1 molar ratio resulted in compounds 1-4 with an almost quantitative yield and five coordinate silicon atoms. Compounds 1-4 were formed by double N-H bond activation by deliberate selection of N,N'-bis-substituted hydrazine compounds bearing the -C(O)NHNH- unit. Compounds 1-4 were characterized by NMR spectroscopy, EI-MS and elemental analysis. The molecular structures of compounds 1-3 were unambiguously established by single crystal X-ray structural analysis.

Highlights

N–H bond activation has been the subject of many studies because of the prevalence of nitrogen-containing compounds for pharmaceutical and other fine chemicals.[1]
We published studies on the N–H bond activation of ammonia[5] and hydrazines,[6,7] and Driess et al outlined the activation for organoamines1g by utilizing the stable N-heterocyclic silylene (NHSi) L [L = CH{(C CH2)(CMe)(2,6-iPr2C6H3N)2}Si]
The choice of the above mentioned substituted hydrazines is based on the fact that the presence of the –NHNH– unit leads to activation of one of the N–H bonds and the presence of the carbonyl group with the –C(O)NHNH– unit favors the formation of a fivemembered ring with L leading to the spirocyclic compound and the activation of the other N–H bond

Summary

Introduction

N–H bond activation has been the subject of many studies because of the prevalence of nitrogen-containing compounds for pharmaceutical and other fine chemicals.[1]. We report on the double N–H bond activation of N,N¢-bis-substituted hydrazines by NHSi (L) leading to compounds 1–4 with five coordinate silicon atoms.

Results

Conclusion