Mild and Efficient PtO2-Catalyzed One-Pot Reductive Mono-N-alkylation of Nitroarenes

Abstract A mild and efficient one-pot reductive monoalkylation of nitroarenes has been described using aldehydes as alkylating agents, molecular hydrogen as a reducing agent, and PtO2 as a catalyst in methanol. This methodology is found to be applicable for both aliphatic and aromatic aldehydes and for a wide variety of nitroarenes. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Commuications® to view the free supplemental file. Keywords: Aldehydecarbonyl compoundnitroarenesplatinum dioxideprotecting groupreductive amination ACKNOWLEDGMENT V. S. R. thanks the University Grant Commission (UGC), New Delhi, for the award of a junior research fellowship. Notes a Reaction conditions: aldehyde (1.5 mmol), nitrobenzene (1 mmol), solvent (5 ml), and PtO2 (8 mol%) at room temperature. b The times given correspond to the following reactions: reduction of nitroarenes + imine formation + reduction of imine. c Reaction conditions: aldehyde (1.0 mmol), nitrobenzene (1.2 mmol), solvent (2 ml), and PtO2 (3 mol%) at room temperature. a Reaction conditions: aldehyde (1.0 mmol), nitrobenzene (1.2 mmol), methanol (2 ml), and PtO2 (3 mol%) at room temperature. b The times given correspond to the following reactions: reduction of nitroarenes + imine formation + reduction of imine. a Reaction conditions: aldehyde (1.0 mmol), nitrobenzene (1.2 mmol), methanol (2 ml), and PtO2 (3 mol %) at room temperature. b The times given correspond to the following reactions: reduction of nitroarenes + imine formation + reduction of imine. c R˭tertiary butyl dimethyl silyl (TBDS).