Insights into sulfinate formation from tosyl hydrazides
作者:Ulf Ragnarsson、Leif Grehn
DOI:10.1016/j.tetlet.2011.12.061
日期:2012.2
Benzylation of 1,2-ditosylhydrazine in DMF under various basic conditions results in a benzyl sulfone via intermediary sulfinate formation, providing new insights and allowing practical conclusions to be drawn. The half-lives of 1,2-ditosylhydrazine and several monotosylated hydrazides with 1,1,3,3-tetramethylguanidine in DMSO have been determined by H-1 NMR spectroscopy and are found to vary from a few minutes to several months. In the course of this work a benzylated, partly detosylated compound has been identified and a 1,1,3,3-tetramethyl guanidine-containing side-product characterized. A contradictory report is also commented on. (C) 2011 Elsevier Ltd. All rights reserved.
An unprecedented rearrangement of a 1,1-diprotected hydrazine derivative. Structure revision of a catalyst-containing by-product
作者:Ulf Ragnarsson、Leif Grehn、Tõnis Pehk
DOI:10.1016/j.tetlet.2014.10.121
日期:2014.12
1-tert-Butoxycarbonyl-1-tosyl-hydrazine as reagent for the synthesis of substituted hydrazines with a secondary alkyl group
作者:Leif Grehn、Ulf Ragnarsson
DOI:10.1016/s0040-4020(99)00156-8
日期:1999.4
suppressed in comparison with that of non- or monoacylated hydrazines, it reacted under various conditions with a representative set of ketones to give the corresponding hydrazones in high yields. The aliphatic hydrazones were readily reduced to hydrazines with NaBH4, whereas the aromatic analogues for smooth reduction required the more powerful NaBH3CN. With one exception all the new compounds were crystalline