Efficient Synthesis of Oxime Using O ‐TBS‐ N ‐Tosylhydroxylamine: Preparation of (2 Z )‐4‐(Benzyloxy)but‐2‐enal Oxime

Abstract

Hydroxylamine hydrochloride Tert ‐Butyldimethylsilylchloride Dimethyformamide Triethylamine p‐ Toluenesulfonyl chloride O ‐TBS ‐N ‐tosylhydroxylamanie Phosphine, triphenyl 4‐Benxyloxy‐2‐buten‐1‐ol DEAD Cesium fluoride

Synthesis and HNO Donating Properties of the Piloty's Acid Analogue Trifluoromethanesulphonylhydroxamic Acid: Evidence for Quantitative Release of HNO at Neutral pH Conditions

“…After numerous failed approaches (see the Supporting Information for details), success was achieved via O ‐silylation. O ‐( tert‐ Butyldimethylsilyl)‐protected N ‐trifluoromethanesulphonylhydroxylamine, CF 3 SO 2 N(H)O‐TBS, was prepared via a one‐pot sequential O ‐silylation/ N ‐sulphonylation reaction of hydroxylamine hydrochloride (see Scheme ) . Purification by drying under high vacuum gave a white solid (35 % yield) that was clean by 1 H and 19 F NMR analysis.…”

Nitrosoallene-Mediated endo-Cyclizations for the Synthesis of (Hetero)cyclic α-Substituted exo-Unsaturated Oximes

“…To a stirred solution of activated 4 Å molecular sieves (400 g/mol based on the substrate), N - tert -butyldimethylsilyloxysulfonamide (1 equiv), and propargyl alcohol (1 equiv) in dichloromethane was added trimethylsilyl trifluoromethanesulfonate (0.5 equiv) at −78 °C under a nitrogen atmosphere. After 30 min, the mixture was warmed up to room temperature and was stirred overnight.…”

“…Using allene chemistry, we have developed transformations of a novel reactive species, nitrosoallenes, which were prepared from N -siloxy- N -allenylsulfonamides through a desilylation/sulfinate elimination sequence . Owing to the strong electronegativity of the nitroso group, these species show characteristic reactivity.…”

Chemoselective, Regioselective, and Enantioselective Allylations of NH2OH under Iridium Catalysis

“… There are some drawbacks in these methods: (a) the protected groups should be removed from the N- or O-group after the allylation reaction; and (b) the steric demand of Bn or Bz decreases the regioselectivity and enantioselectivity. The use of NH 2 OH in such a reaction, giving the allylated hydroxylamine derivatives, has not been reported until now. The allylated hydroxylamine derivatives are of great importance to [2,3]-sigmatropic rearrangement .…”