Hexafluoroisopropyl Sulfamate: A Useful Reagent for the Synthesis of Sulfamates and Sulfamides
Matthew A. Sguazzin, Jarrod W. Johnson* and Jakob Magolan*
*Department of Biochemistry & Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 3Z5, Canada,
Email: johnsj13
mcmaster.ca, magolanjmcmaster.ca
M. A. Sguazzin, J. W. Johnson, J. Magolan, Org. Lett., 2021, 23, 3373-3378.
DOI: 10.1021/acs.orglett.1c00855
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Abstract
Hexafluoroisopropyl sulfamate is as a bench-stable solid that reacts readily with a wide variety of alcohols, amines, phenols, and anilines under mild reaction conditions to provide sulfamates and sulfamides. The sole byproduct of the reaction is hexafluoroisopropanol and reaction products can often be isolated in high purity after a simple workup.
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proposed mechanism
General Procedure for sulfamides and alkyl sulfamates
Hexafluoroisopropyl sulfamate (148 mg, 0.6 mmol) was added to a solution of alcohol (0.5 mmol) in CH2Cl2 (3.5 mL) and pyridine (1.5 mL) and stirred at 30°C for 8-18h. The reaction mixture was concentrated under reduced pressure via rotary evaporation (with a bath temperature up to 50°C) and often co-evaporated with PhMe (15 mL) to aid in pyridine removal. The crude mixture was chromatographed on silica gel to provide the sulfamate or sulfamide product.
General Procedure for aryl sulfamates and other sulfamates sensitive to thermal and/or base-induced decomposition
Hexafluoroisopropyl sulfamate (148 mg, 0.6mmol) was added to a solution of a phenol or alcohol (0.5 mmol) in CH2Cl2 (3.5 mL) and pyridine (1.5 mL) and stirred at 30°C for 18 h. The solution was then diluted with CH2Cl2* (20mL) and washed with 10% HCl (20 mL). The resulting aqueous layer was extracted with CH2Cl2* (3× 20 mL) and the combined organic extracts were washed with H2O (3 × 20mL), and satd NaCl (20 mL), dried over Na2SO4, and concentrated under reduced pressure. Sulfamate products were purified by silica gel chromatography.* Some sulfamates showed poor solubility in CH2Cl2 and were extracted more efficiently with Et2O or EtOAc.
Key Words
ID: J54-Y2021
