Aim and Objective:
The direct β-functionalization of trans-β-nitroolefins by Michael reaction is regarded
as an efficient way to provide precursors for β-functional amines. However, Michael additions by grinding
means with solvent-free conditons are rarely reported. We have developed facile access to
β-functional nitroalkanes by grinding means under solvent-free conditions.
Materials and Methods:
From commercially available materials including ethyl 2-nitroacetate, alkyl
2-cyanoacetates and malononitrile, the grinding reactions between these above-mentioned activated methylenecompounds
and various trans-β-nitroolefins were performed at room temperature and solvent-free conditions.
Results:
A highly efficient direct Michael reaction of nitroolefins by simple grinding means has been
developed. Various trans-nitrostyrenes were easily converted into corresponding β-functional nitroalkanes in
excellent yields within 5~10 min (up to 36 examples).
Conclusion:
Herein, we have developed a simple and efficient way to β-functional nitroalkanes through
Michael reactions by grinding means. The grinding Michael reaction is fast, clean and stable and these Michael
adducts could be easily converted into the other amino compounds served as building blocks in organic
synthesis.
Hydroboration of nitriles and imines by highly active zinc dihydride catalysts