Sodium Hypochlorite, Bleach, NaOCl
Sodium hypochlorite is an inexpensive, strong oxidizing agent, that is used as disinfectant and bleaching agent. It is unstable as a solid, but solutions of up to 40% are commercially available that contain NaOH and NaCl as byproducts of the preparation:
2 NaOH + Cl2 → NaCl + NaOCl + H2O
Hypochlorite solutions liberate toxic gases such as chlorine when acidified or heated. The reaction with ammonia or with substances that can generate ammonia can produce chloramines which are also toxic and have explosive potential.
Name Reactions
Recent Literature
TEMPO-derived reagents tagged with multiple perfluoroalkyl chains and
triazole moieties promote the oxidation of alcohols to aldehydes in organic
solvent/water mixtures with reaction rates comparable to homogeneous TEMPO
reagents, but can be easily recovered by liquid/emulsion filtration.
A. Gheorghe, T. Chinnusamy, E. Cuevas-Yañez, P. Hilgers, O. Reiser, Org. Lett.,
2008,
10, 4171-4174.
Sodium hypochlorite pentahydrate crystals with very low NaOH and NaCl contents
oxidize primary and secondary alcohols to the corresponding aldehydes and
ketones in the presence of TEMPO/Bu4NHSO4 without pH
adjustment. This new oxidation method is also applicable to sterically hindered
secondary alcohols.
T. Okada, T. Asawa, Y. Sugiyama, M. Kirihara, T. Iwai, Y. Kimura, Synlett, 2014, 25,
596-598.
A stable nitroxyl radical class of catalysts, 2-azaadamantane N-oxyl (AZADO) and
1-Me-AZADO, exhibit superior catalytic proficiency to TEMPO, converting various
sterically hindered alcohols to the corresponding carbonyl compounds in
excellent yields.
M. Shibuya, M. Tomizawa, I. Suzuki, Y. Iwabuchi, J. Am. Chem. Soc., 2006,
128, 8412-8413.
Silica-supported TEMPO is easily obtained in a one-step reductive amination
procedure starting from a commercially available aminopropyl-functionalized
silica. This supported catalyst mediates the Anelli oxidation of various
alcohols. The recyclability and stability of the applied silica-supported TEMPO
have been studied.
T. Fey, H. Fischer, S. Bachmann, K. Albert, C. Bolm, J. Org. Chem., 2001,
66, 8154-8159.
The use of NaClO/TEMPO/Co(OAc)2 enabled a benzylic oxidation of alkyl
arenes to yield various aromatic aldehydes and ketones in very good yields. The
reaction reactivity, selectivity, and scope of the reaction were investigated.
C. Jin, L. Zhang, W. Su, Synlett, 2011,
1435-1438.
An efficient and practical method enables the synthesis of unsymmetric benzils
from readily available β-ketoaldehydes via oxidation by sodium hypochlorite,
decarboxylation, and chlorination with Cl2 generated from sodium
hypochlorite. Various unsymmetric 1,2-diaryldiketones bearing functional groups
have been obtained in very good yields under mild reaction conditions.
L. Ruan, M. Shi, N. Li, X. Ding, F. Yang, J. Tang, Org. Lett., 2014,
16, 733-735.
A general procedure for the osmium-catalyzed dihydroxylation of various
terminal and internal olefins using bleach as cheap oxidant yields the
corresponding cis-1,2-diols in the presence of dihydroquinine or
dihydroquinidine derivatives (Sharpless ligands) with good to excellent chemo-
and enantioselectivities under optimized pH conditions.
G. M. Mehltretter, S. Bhor, M. Klawonn, C. Döbler, U. Sundermeier, M. Eckert,
H.-C. Militzer, M. Beller, Synthesis,
2003, 295-301.
Promising, dual-functioning chiral catalysts for the highly enantioselective
epoxidation of α,β-unsaturated ketones gave epoxy chalcones in excelllent
yield and high enantioselectivity using 13% NaOCl as oxidizing agent in
toluene under mild phase-transfer conditions.
T. Ooi, D. Ohara, M. Tamura, K. Maruoka, J. Am. Chem. Soc., 2004,
126, 6844-6845.
Readily available Mn(III) complexes catalyze alkene epoxidation by bleach in
good yields. A highly enantioselective epoxidation catalyst was developed
through a logical sequence of ligand modifications.
E. N. Jacobsen, W. Zhang, A. R. Muci, J. R. Ecker, L. Deng, J. Am. Chem.
Soc., 1991,
113, 7063-7064.
Iodine catalyzes stereospecific 1,2-diaminations of unactivated alkenes.
Depending on the nitrogen source and the configuration of the alkenes, two
methods provide access to all disastereomeric forms of 1,2-diamines.
S. Minakata, H. Miwa, K. Yamamoto, A. Hirayama, S. Okumura, J. Am. Chem. Soc.,
2021, 143, 4112-4118.
A catalyst-free oxidation of sulfides with sodium hypochlorite pentahydrate
crystals in an aqueous acetonitrile solution selectively produces the
corresponding sulfoxides in high yields in an environmentally benign fashion.
T. Okada, H. Matsumuro, S. Kitagawa, T. Iwai, K. Yamazaki, Y. Kinoshita, Y.
Kimura, M. Kirihara,
Synlett, 2015, 26, 2547-2552.
A clean and economic synthesis of alkanesulfonyl
chlorides via bleach-mediated oxidative chlorosulfonation of S-alkyl isothiourea
salts is simple, environment- and worker-friendly. The procedure uses readily accessible reagents,
offers safe
operations and easy purification without chromatography, and affords high yields.
Z. Yang, B. Zhou, J. Xu, Synthesis, 2014, 46,
225-229.
A Pd-catalyzed coupling of aryl iodides and the sulfur dioxide surrogate DABSO
provides aryl ammonium sulfinates, that can be transformed in a one-pot process
to various functionalized sulfonamides by simple treatment with an aqueous
solution of the relevant amine and sodium hypochlorite (bleach). A broad range
of amines, including anilines, and amino acid derivatives can be used.
E. F. Flegeau, J. M. Harrison, M. C. Willis,
Synlett, 2016, 27, 101-105.
Sodium hypochlorite pentahydrate (NaClO·5H2O) enables an
inexpensive, safe, and rapid oxidation of iodoarenes to provide synthetically
useful (diacetoxyiodo)arenes as precursors of various organo-λ3-iodanes such as hydroxyl(tosyloxy)iodobenzene, iodosylbenzene, iodonium ylide, etc.
A. Watanabe, K. Miyamoto, T. Okada, T. Asawa, M. Uchiyama, J. Org. Chem., 2018, 83,
14262-14268.
The use of cheap and innocuous reagents, such as NaClO2, NaOCl,
and catalytic amounts of TEMPO enables an environmentally friendly C(sp3)-H
oxidation of piperazines and morpholines to 2,3-diketopiperazines and
3-morpholinones, respectively. In addition, by using a stoichiometric amount of
TEMPO, 2-alkoxyamino-3-morpholinones can be prepared from morpholine derivatives.
D. Chamorro-Arenas, U. Osorio-Nieto, L. Quintero, L. Hernández-García, F.
Sartillo-Piscil, J. Org. Chem., 2018, 83,
15333-15346.
A concise and practical protodeboronation of arylboronic acids works under mild conditions in aqueous NaClO at 100°C. The strategy
is low-cost, transition-metal-free, and base-free.
M. Li, Y. Tang, J. Gao, G. Rao, Z. Mao, Synlett, 2020,
31,
2039-2042.
A divergent and regioselective synthesis of either 3-substituted benzisoxazoles
or 2-substituted benzoxazoles from readily accessible ortho-hydroxyaryl
N-H ketimines proceeds in two distinct pathways through a common N-Cl imine
intermediate: (a) N-O bond formation to form benzisoxazole under anhydrous
conditions and (b) NaOCl mediated Beckmann-type rearrangement to form
benzoxazole, respectively.
C.-y Chen, T. Andreani, H. Li, Org. Lett., 2011,
13, 6300-6303.
Bleach oxidizes trimethylsilyl cyanide to generate an electrophilic cyanating
reagent that readily reacts with an amine nucleophile. This oxidative N-cyanation
reaction enables the synthesis of disubstituted cyanamides without using highly
toxic cyanogen halides.
C. Zhu, J.-B. Xia, C. Chen, Org. Lett., 2014,
16, 247-249.
