Reaction of InCl3 with Various Reducing Agents: InCl3鈥揘aBH4-Mediated Reduction of Aromatic and Aliphatic Nitriles to Primary Amines

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• 作者：Jaime Z. Saavedra ; Angel Resendez ; Alexander Rovira ; Scott Eagon ; Dustin Haddenham ; Bakthan Singaram
• 刊名：The Journal of Organic Chemistry
• 出版年：2012
• 出版时间：January 6, 2012
• 年：2012
• 卷：77
• 期：1
• 页码：221-228
• 全文大小：336K
• 年卷期：v.77,no.1(January 6, 2012)
• ISSN：1520-6904

文摘

While alternative methods of preparing dichloroindium hydride (HInCl₂) via the in situ reduction of InCl₃ using lithium amino borohydride (LAB) were explored, generation of HInCl₂ from the reduction of InCl₃ by sodium borohydride (NaBH₄) was also re-evaluated for comparison. The reductive capability of the InCl₃/NaBH₄ system was found to be highly dependent on the solvent used. Investigation by ¹¹B NMR spectroscopic analyses indicated that the reaction of InCl₃ with NaBH₄ in THF generates HInCl₂ along with borane鈥搕etrahydrofuran (BH₃路THF) in situ. Nitriles underwent reduction to primary amines under optimized conditions at 25 掳C using 1 equiv of anhydrous InCl₃ with 3 equiv of NaBH₄ in THF. A variety of aromatic, heteroaromatic, and aliphatic nitriles were reduced to their corresponding primary amine in 70鈥?9% isolated yields. Alkyl halide and nitrile functional groups were reduced in tandem by utilizing the reductive capabilities of both HInCl₂ and BH₃路THF in a one-pot reaction. Finally, the selective reduction of the carbon bromine bond in the presence of nitriles was achieved by generating HInCl₂ via the reduction InCl₃ with NaBH₄ in CH₃CN or with lithium dimethylaminoborohydride (MeLAB) in THF.