processes of this reaction using molecular hydrogen as a
hydrogen source are an unresolved task for chemoselective
organic transformations. Here, we used a polysilane-alumina-
present system is space saving and can be operated safety. Partial
hydrogenation of the resulting nitroolefins gives evolved
nitroalkanes; thus, various types of nitroalkanes and nitroolefins
will be accessible by using these techniques.
4
1
based heterogeneous Pd catalyst developed by us previously.
A
stream of nitroolefination furnishing 3i (0.05 mL/min) was
attached to a Y-shaped connector, and methanol was flowed from
the other side at a rate of 0.05 mL/min. The resulting toluene–
methanol solution of 3i was introduced to a second column
containing polydimethylsilane (PDMSi)-Pd/alumina and Celite
Acknowledgments
This work was partially supported by a Grant-in-Aid for
Science Research from the Japan Society for the Promotion of
Science (JSPS), Global COE Program, The University of Tokyo,
MEXT, Japan, and the Japan Science and Technology Agency
(JST).
(
1:1) mounted with a hydrogen gas inlet. The desired
hydrogenation proceeded smoothly at room temperature to afford
the corresponding nitroalkane 1i in good yield and with high
product selectivity. The 60–70% yields of 1i were reflected in the
yield of nitroolefination, and the unreacted aldehyde 2i from the
first column was found; however, neither fully hydrogenated
amine nor its intermediates were detected from the outlet.
References and notes
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