Organometallics
Article
EXPERIMENTAL SECTION
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General Considerations. All manipulations were carried out
using standard nitrogen drybox techniques. Anhydrous acetonitrile,
copper(I) iodide, copper(I) chloride, potassium phosphate, most aryl
chlorides (except 1,4-dichlorobenzene from TCI), most amides
(except trimethylacetamide from Aldrich), and n-decane were
purchased from Acros and used as received. trans-N,N′-Dimethylcy-
clohexane-1,2-diamine was purchased from Acros and Aldrich and
was used as received. Potassium carbonate was purchased from
Aldrich and oven-dried before use. Microwave reactions were
performed in a CEM Discover SP microwave reactor with IR
temperature monitoring and Activent technology to prevent unsafe
overpressurization of the reaction tube. GC-MS analysis was
performed on a Shimadzu GCMS-QP5050A with a Restek Rxi-5 ms
capillary column (30 m, 0.25 mm ID, 0.25 μm film thickness, 5%
AUTHOR INFORMATION
Corresponding Authors
ORCID
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Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
diphenyl/95% dimethylpolysiloxane). H and 13C NMR spectra were
recorded on a JEOL ECX-400 spectrometer and were referenced to
residual protio solvent peaks. Melting points were measured on an
Electrothermal Mel-temp device.
1
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R.K.C. and B.P.C. gratefully acknowledge the Office of Naval
Research for partial support of this work on funding document
NN00014110WX30241. R.K.C. gratefully acknowledges Dr.
Ned Garrigues (USNA Class of 1968). S.L. and A.H.R.M.
thank James W. Kinnear (USNA Class of 1950), the Naval
Academy Research Council, and the Office of Naval Research
for partial support of this work on funding document
N0001409WR40059.
General Procedure for the Cu-Catalyzed Amidation of Aryl
Chlorides. In a nitrogen-filled glovebox, copper(I) iodide (38 mg,
0.20 mmol, 20 mol %), trans-N,N′-dimethylcyclohexane-1,2-diamine
(85 mg, 0.60 mmol, 60 mol %), amide (1.05 mmol), potassium
carbonate (304 mg, 2.2 mmol), and aryl chloride (1.00 mmol) were
weighed into an oven-dried microwave tube containing a small stir
bar. Acetonitrile (0.5 mL) was added by syringe and the sample was
stirred for approximately 10 s. The initial reaction mixture appeared to
be a transparent, colorless or pale yellow liquid over a white, granular
solid. The tube was then capped and removed from the nitrogen
glovebox and immediately placed in a CEM Discover microwave
reactor for 60 min at 200 °C and 150 W (with power adjustments to
maintain temperature) following a 2−3 min ramp time. After cooling,
the reaction mixture contained a dark brown liquid over a solid, but
the color of the solid was difficult to determine due to the dark color
of the liquid. The reaction was quenched with 2 mL of 30% aqueous
ammonia solution and transferred to a separatory funnel, and the
product was extracted with 3 × 20 mL of ethyl acetate. The product
was then washed with 2 × 20 mL of distilled water and dried over
magnesium sulfate. The organic solvent was evaporated under vacuum
and the resulting product was purified by column chromatography on
silica. The reaction conditions and average yields for each reaction are
shown in Table 2 and Table 3.
General Procedure for the Cu-Catalyzed Amidation of 4-
Bromotoluene. In a nitrogen-filled glovebox, either copper(I) iodide
(38 mg, 0.20 mmol, 20 mol %) or copper(I) bromide (30 mg, 0.21
mmol, 20 mol %) was mixed with trans-N,N′-dimethylcyclohexane-
1,2-diamine (57 mg, 0.40 mmol, 40 mol %), benzamide (126 mg, 1.04
mmol), potassium phosphate (423 mg, 1.99 mmol), and 4-
bromotoluene (171 mg, 1.00 mmol) in an oven-dried microwave
tube containing a small stir bar. Solvent (1,4-dioxane, 0.5 mL) was
added by syringe. The tube was then capped and removed from the
nitrogen glovebox and immediately placed in a CEM Discover
microwave reactor for 60 min at 80 °C and 50 W (with power
adjustments to maintain temperature) following a 1 min ramp time.
After cooling, an equimolar amount (versus ArCl) of n-decane (141.7
mg, 0.996 mmol) was added. The reaction was quenched with 2 mL
of 30% aqueous ammonia solution, and the product was extracted
with 2 mL of ethyl acetate. The solids in the mixture were dispersed
using the pre-existing stir bar and a stir plate. Then, 10 μL of the top
(organic) layer was taken from the sample and placed in a small vial
containing 2 mL of ethyl acetate. This sample was then analyzed by
GC-MS.
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ASSOCIATED CONTENT
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* Supporting Information
The Supporting Information is available free of charge on the
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(14) Falk, F. C.; Frohlich, R.; Paradies, J. Coupling of Ortho-
Substituted Aryl Chlorides with Bulky Amides. Chem. Commun. 2011,
47 (39), 11095−11097.
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Organometallics XXXX, XXX, XXX−XXX