One-pot o-nitrobenzenesulfonylhydrazide (NBSH) formation-diimide alkene reduction protocol

Article abstract of DOI:10.1021/jo900237y

A one-pot protocol for the formation of 2-nitrobenzenesulfonylhydrazide (NBSH) from commercial reagents and subsequent alkene reduction is presented. The transformation is operationally simple and generally efficient for effecting diimide alkene reductions. A range of 16 substrates have been reduced, highlighting the unique chemoselectivity of diimide as a reduction system.

Full text of DOI:10.1021/jo900237y

Supporting Information
S1
One-Pot o-Nitrobenzenesulfonylhydrazide (NBSH) Formation -
Diimide Alkene Reduction Protocol
Barrie Marsh and David R. Carbery
Department of Chemistry, University of Bath, Bath, BA2 7AY, UK.
Supporting Information
Contents
Page
S1
General Information
Experimental Section
S2
NMR Spectra Displaying % Conversions
NMR Spectra of New Compounds (22)
References
S9
S17
S18
I. General.
Reactions were carried out using dry solvents under an inert atmosphere of nitrogen.
All reaction flasks were dried overnight in an oven at 200 °C prior to use. Acetonitrile
was dried by passing through anhydrous alumina columns. All reagents were
purchased from commercial suppliers and used without further purification. 2-
Nitrobenzenesulfonyl hydrazide was prepared according to the procedure published
by Myers.1 2-Methyl phenyl acrylate was prepared according to the procedure
reported by Davies.2 Chemical shifts are reported in parts per million relative to
tetramethylsilane (TMS) (δ = 0.00). Mass spectroscopy was performed using
electrospray ionisation (ESI) in positive ionisation mode. Infra-red spectroscopy was
performed with KBr plates.

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II. Diimide Hydrogenations
General Procedure A for the Hydrogenation of Methyl-2-phenyl acrylate using 2-
Nitrobenzenesulfonylhydrazine as a diimide precursor.
2-Nitrobenzenesulfonylhydrazide (434 mg, 2 mmol) and additive (1 mmol) were
dissolved in solvent (5 cm3) and allowed to stir for 10 mins under N2. Methyl-2-
phenyl acrylate (162mg, 1 mmol) in solvent (1 cm3) was slowly added by syringe
over the course of 1 minute. The solution was allowed to stir for 18 hrs. After which
time the orange solution was treated with H2O (5 cm3), the product was extracted with
EtOAc (3 × 5 cm3) and the combined organic extracts were washed with NaHCO3
(sat) (10 cm3) and brine (sat) (10 cm3). The combined organic extracts were then dried
over MgSO4 and filtered. Solvent was removed in vacuo to give the methyl-2-
phenylpropanoate as a crude oil.
General Procedure B for the One Pot Synthesis of NBSH-Alkene Hydrogenation.
The 2-nitrobenzenesulfonyl chloride (442 mg, 2 mmol) and the alkene (1 mmol) were
°
dissolved in dry MeCN (5 cm3 / mmol of alkene) and cooled to 0 C. Once cold the
hydrazine hydrate (194 ꢀl, 4 mmol) was slowly added down to side of the reaction
flask (over a period of 1 min) to the vigorously stirred solution of the alkene and 2-
nitrobenzenesulfonyl chloride. The resulting white suspension was slowly allowed to

Supporting Information
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warm to room temperature and stirred vigorously for a further 18 hours. The product
was worked up by various methods:
Work Up Method I: After this time the orange suspension was quenched by addition
of H2O (5 cm3) product was extracted with EtOAc (4 × 5 cm3), the combined organic
extracts were then washed with saturated NaHCO3 (10 cm3) and brine (sat) (10 cm3).
The combined organic extracts were then dried over MgSO4 and filtered. Solvent was
removed in vacuo to give the desired crude product.
Work Up Method II: After this time the orange suspension was quenched by
addition of H2O (5 cm3) product was extracted with pentane (4 × 5 cm3), the
combined organics were then dried over MgSO4 and filtered. Solvent was removed in
vacuo to give the crude product.
Work Up Method III: After this time the orange suspension was filtered, and the
filtrate washed with EtOAc (10 cm3), the organics were then dried over Na2SO4.
Solvent was then removed in vacuo to give the crude product.
Percentage conversions are determined using equation 1, using appropriate
integrations of appropriate starting material peaks (if present) and product peaks in the
1H NMR of crude reaction mixtures using the following equation:
Equation 1
Data labels annotated upon crude 1H NMR are as follows:
Red: Product protons used for conversion calculation labelled Hp.
Green: Starting material protons used for conversion calculations labelled HSM.
Blue: Residual NBSH carried through work up.

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Methyl-2-phenylpropanoate 6.3
The title compound was obtained using general procedure B and work up method I
1
for 18 hours using methyl-2-phenyl acrylate (162 mg, 1 mmol). H NMR indicated
100% conversion of the starting material, the identity of the title compound was
confirmed by comparison with previously published spectral data in the literature.3
Methyl-2-acetamidopropanoate 8.
The title compound was obtained using general procedure B and work up method I
for 42 hours using methyl-2-acetamidoacyralte (143 mg, 1 mmol). 1H NMR indicated
78% conversion of the starting material to the desired compound, the identity of
which was confirmed by comparison with commercially available material.
2-Hydroxy ethyl isobutyrate 9.4
The title compound was obtained using general procedure B and work up method I
1
for 42 hours using 2-hydroxy ethyl methyl acrylate (130 mg, 1 mmol). H NMR
indicated 100% conversion of the starting material to the desired compound, the
identity of which was confirmed by comparison with published spectral data in the
literature.4
Propyl benzylether 10.
The title compound was prepared using general procedure B and work up method I
1
for 18 hours using allyl benzyl ether (148 mg, 1mmol). H NMR indicated 99%
conversion of the starting material to the desired product, the structure of which was
confirmed by comparison with an authentic commercially available source.

Supporting Information
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Benzyl propylcarbamate 11.5
The title compound was prepared using general procedure B and work up method I
for 18 hours using benzyl allylcarbamate (190 mg, 1 mmol). 1H NMR indicated 100%
conversion of the starting material to the desired product, the structure of which was
confirmed by comparison with previously recorded literature data for the title
compound.5
Phenylpropylsulfide 12.5
The title compound was prepared using general procedure B and work up method I
1
for 18 hours using allyl phenyl sulphide (150 mg, 1 mmol). H NMR indicated 98%
conversion of the starting material to the desired product, the structure of which was
confirmed by comparison with previously reported spectral data from the literature.5
Cylcohexanol 13.
The title compound was obtained using general procedure B and work up method I
1
for 18 hours using 2-cyclohexen-1-ol (98 mg, 1mmol). H NMR indicated 46%
conversion of the starting material to the desired product, the structure of which has
confirmed by comparison with an authentic commercially available source.
2,3-Norbornanedimethanol 14.5
The title compound was obtained using general procedure B and work up method I
1
for 18 hours using 5-norborene-2-exo-3-exo-dimethanol (154 mg, 1mmol). H NMR
indicated 100% conversion of the starting material to the desired product, the
structure of which was confirmed by comparison with previously published spectral
data.5

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2-Ethylpyridine 15.
The title compound was obtained using general procedure B and work up method I
1
for 18 hours using 2-vinyl pyridine (105 mg, 1 mmol). H NMR indicated 100% of
the starting material to the desired product, the structure of which was confirmed by
comparison with authentic commercial material.
(R)-4-Isopropyl-1-methylcyclohex-1-ene 16.
The title compound was obtained using general procedure B and work up method I
for 42 hours using (R)-(+)-limonene (136 mg, 1mmol). 1H NMR indicated 72% of the
starting material to the desired product, the structure of which was confirmed by
comparison with an authentic commercial material.
Cyclooctane 17.
The title compound was obtained using general procedure B and work up method II
1
for 18 hours cis-cyclooctane (110 mg, 1mmol). H NMR indicated 100% conversion
of the starting material to the desired product, the structure of which was confirmed
by comparison with authentic commercial material.
Propylbenzene 18.
The title compound was obtained using general procedure B and work up method II
for 18 hours using trans-β-methyl styrene (118 mg, 1 mmol). 1H NMR indicated 61%
conversion of the starting material to the desired product, the structure of which was
confirmed by comparison with authentic material from a commercial supplier.

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3-Ethylnitrobenzene 19.
NO2
The title compound was obtained using general procedure B and work up method I
1
for 18 hours using 3-nitro-styrene (149 mg, 1 mmol). H NMR indicated 100%
conversion of the starting material to the desired product, the structure of which was
confirmed by comparison with commercially available material.
2-Acetamidopropanoic acid 20.
The title compound was obtained using general procedure B and work up method III
1
for 18 hours using 2-acetamido acrylic acid (129 mg, 1 mmol). H NMR indicated
87% conversion of the starting material to the desired product, the structure of which
was confirmed by comparison with authentic sample from a commercial supplier.
Methyl 2-Phenylhexanoate 21.6
The title compound was obtained using general procedure B and work up method I
for 18 hours using methyl-phenyl-but-2-enoate (2:1 mixture of isomers) (204 mg,
1
1mmol). H NMR indicated 8% conversion of the starting material to the desired
product, the structure of which was confirmed by comparison with previously
reported spectral data.6
2-Propyl-acetamidoacrylate 22.
The title compound was obtained using general procedure B and work up method II
for 18 hours using 2-allyl-acetamidoacyrlate (169 mg, 1mmol). Product was purified
via column chromatography eluting with 25% EtOAc : petrol (40:60) to give the title

Supporting Information
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compound as a clear oil (147 mg, 86%). νmax (flim)/cm-1 2970, 2881, 1719, 1674,
1
1634, 1509; H NMR (500 MHz; CDCl3) δH 0.96 (3H, t, J=7.7 Hz), 1.71 (2H, qt,
J=7.7, 6.7 Hz), 2.10 (3H, s), 4.17 (2H, t, J=6.7 Hz), 5.85 (1H, d, J=1.4 Hz), 6.55 (1H,
13
s), 7.74 (1H, br s); C NMR (125 MHz, CDCl3) δC 10.5, 22.1, 24.9, 67.9, 108.3,
131.3, 164.4, 168.9; m/z (ESI) 194.0781 (95%, [M-Na]+ C8H13NO3Na requires
194.0793).

Supporting Information
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Methyl-2-phenylpropanoate 6.
Methyl-2-acetamidopropanoate 8.
HP
HSM

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2-Hydroxy ethyl isobutyrate 9.
O
O
H
H
OH
100%
conversion
Propyl benzylether 10.
O
Ph
HP
H
O
Ph
HSM
99%
conversion
HP
HSM

Supporting Information
S11
Benzyl propylcarbamate 11.
H
H
NHCbz
100%
conversion
Phenylpropylsulfide 12.
HP
SPh
HSM
H
SPh
98%
conversion
HP
HSM

Supporting Information
S12
Cylcohexanol 13.
HSM OH
HP OH
43%
H
H
conversion
HSM
HP
2,3-Norbornanedimethanol 14.
H
H
OH
OH
100%
conversion

Supporting Information
S13
2-Ethyl pyridine 15.
N
H
H
100%
conversion
(R)-4-Isopropyl-1-methylcyclohex-1-ene 16.
H
HSM
HP
72%
conversion
HSM
HP
HSM

Supporting Information
S14
Cyclooctane 17.
H
H
100%
converision
Propylbenzene 18.
HSM
HP
H
HSM
61%
conversion
HP
HSM

Supporting Information
S15
2-Ethyl-nitrobenzene 19.
H
H
100%
conversion
NO2
2-Acetamidopropanoic acid 20.
AcHN
CO2H
HSM
AcHN
CO2H
HP
H
87%
conversion
HSM
HP

Supporting Information
S16
Methyl 2-Phenylhexanoate 21.
Ph
CO2Me
Ph
CO2Me
HP
H
n-Pr
HSM
n-Pr
8 %
conversion
E : Z (3:1)
HSM HSM
HP
(See Expansion for clearer image)
Me
Ph
H
CO2Me
Ph
HP
H
CO2Me
n-Pr
n-Pr
8 %
conversion
E : Z (3:1)
Me
Me
HP

Supporting Information
2-Propyl-acetamidoacrylate 22.
AcHN
S17
O
O

Supporting Information
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References
(1). Myers, A. G; Zheng, B. J. Am. Chem. Soc. 1996, 118, 4492.
(2) Beddow, J. E.; Davies, S. G.; Ling, K. B.; Roberts, P. M; Russell, A. J.; Smith, A.
D., Thomson, J. E. Org. Biomol. Chem. 2007, 5, 2812.
(3) Durandetti, M; Gosmini, C; Perichon, J. Tetrahedron 2006, 63, 1146.
(4). Imada, Y; Iida, H; Naota, T. J. Am. Chem. Soc. 2005, 127, 14544.
(5). Hattori, K; Sajiki, H; Hirota, K. Tetrahedron 2000, 56, 8433.
(6) Liu, C; He, C; Shi, W; Chen, M; Lei, A. Org. Lett. 2007, 9, 5601.