Various olefins can be hydrogenated quantitatively with neutral, flavin-derived catalysts in the presence of hydrazine under an athomspheric pressure of O2. A vitamin B2 derivative acts as a highly efficient and robust catalyst for the environmentally benign process producing water and nitrogen gas as the only waste products.
Y. Imada, T. Kitagawa, T. Ohno, H. Iida, T. Naota, Org. Lett., 2010, 12, 32-35.
Olefins can be hydrogenated by treatment with hydrazine in the presence of a 5-ethyl-3-methyllumiflavinium perchlorate catalyst under O2 atmosphere to give the corresponding hydrogenated products in excellent yields along with environmentally benign water and molecular nitrogen as the only waste products.
Y. Imada, H. Iida, T. Naota, J. Am. Chem. Soc., 2005, 127, 14544-14545.
Whereas an Ir-catalyzed alcohol deoxygenation on basis of dehydrogenation/Wolff-Kishner reduction is efficient mainly with activated alcohols under harsh reaction conditions, a Ru-catalyzed aliphatic primary alcohol deoxygenation offers good functional group tolerance and excellent efficiency under practical reaction conditions. Its synthetic utility is further illustrated by complete chemo- and regio-selectivity in complex molecular settings.
X.-J. Dai, C.-J. Li, J. Am. Chem. Soc., 2016, 138, 5344-5440.
Several bromo, chloro, iodo and multihalogenated nitroarenes have been selectively reduced with hydrazine hydrate in the presence of Pd/C to give the corresponding halogenated anilines in good yield. Using microwave irradiation at elevated temperature and pressure, dehalogenated products can be isolated.
F. Li, B. Frett, H.-y Li, Synlett, 2014, 25, 1403-1408.
Visible-light mediates a scalable and operationally simple method for the chemoselective deoxygenation of a wide range of N-heterocyclic N-oxides at room temperature using only commercially available reagents. This protocol offers an unprecedented chemoselective removal of the oxygen atom in a quinoline N-oxide in the presence of a pyridine N-oxide through the judicious selection of the photocatalyst.
K. D. Kim, J. H. Lee, Org. Lett., 2018, 20, 7712-7716.
A facile protocol for the reduction of aromatic ketones and aldehydes to the corresponding methylene unit involves the synthesis of a carbomethoxyhydrazone intermediate that is easily decomposed to the reduced product. The reaction avoids the use of pernicious hydrazine.
P. B. Cranwell, A. T. Russell, C. D. Smith, Synlett, 2016, 27, 131-135.