Sodium Hypochlorite Pentahydrate Crystals (NaOCl·5H₂O): A Convenient and Environmentally Benign Oxidant for Organic Synthesis

Abstract

The novel oxidant of sodium hypochlorite pentahydrate (NaOCl·5H2O) crystals is now available for industrial and laboratory use. It is superior to conventional aqueous sodium hypochlorite solutions (aq. NaOCl). The crystalline material is 44% NaOCl and contains minimal amounts of sodium hydroxide and sodium chloride, and the aqueous solution, which is prepared from NaOCl·5H2O and water, has a pH of 11–12. Examples of the selective organic synthesis using NaOCl·5H2O involve the oxidations of primary and secondary alcohols, selective oxidations to sulfoxide and sulfone, oxidative cleavage of disulfide to sulfonyl chloride and bromide, oxaziridine synthesis, and oxidative dearomatization of phenols.

Selective TEMPO‐Oxidation of Alcohols to Aldehydes in Alternative Organic Solvents

“…Usually, for TEMPO‐catalysed oxidation bromide ions were used as a co‐catalyst, since the in situ‐formed hypobromite is even more reactive than hypochlorite and was reported to represent the actual oxidation agent in this process , . The Kimura group found, however, that bromide is not necessary when using the pentahydrate as oxidation agent as long as a phase‐transfer catalyst or additives like NaHSO 4 are used , . To get a deeper insight into the reaction system of Kimura et al, we first investigated the influence of different phase‐transfer catalysts and additives.…”

Regioselective Oxidative Chlorination of Arenols Using NaCl and Oxone

“…42 %), lower pH upon dissolution (pH ca. 11) and high stability at lower temperatures . We envisioned that NaOCl · 5H 2 O could be applied as a chlorinating agent to the chlorinative dearomatization of arenols in the absence of an intramolecular nucleophilic moiety at an appropriate position (Scheme b).…”

Mg-Catalyzed OPPenauer Oxidation—Application to the Flow Synthesis of a Natural Pheromone

“…Pivaldehyde [14] was selected as the first hydride acceptor owing to its low dielectric constant and high oxidation potential (E 0 = 211 mV) [19]. Different magnesium oxides and a magnesium salt were studied to see if the OPP oxidation could be performed with catalytic amounts of these species (Table 1).…”

“…To overcome this sluggish activity, some typical procedures involving a broad range of organic oxidizing reagents and metal-based systems have emerged. Simple salts as K [16,17] and Na [18,19] were first used in respectively stoichiometric and catalytic quantities to promote the OPP oxidation while more complex metal-based systems rapidly arose. Most of them were involving transition metals such as Ru [20,21], Ir [22,23], Fe [24], Zr [25] or more recently Mn [26], used in catalytic amounts but also other elements such as In [27,28], or Si [29].…”