Direct Synthesis of Nitriles from Aldehydes Using an O-Benzoyl Hydroxylamine (BHA) as the Nitrogen Source

Abstract

The direct synthesis of nitriles from commercially available or easily prepared aldehydes has been achieved. O-(4-CF3-benzoyl)-hydroxylamine (CF3-BHA) was utilized as the nitrogen source to generate O-acyl oximes in situ with aldehydes, which can be converted to a nitrile with the assistance of a Brønsted acid. Several aliphatic, aromatic, and α,β-unsaturated nitriles that contain different functional groups were prepared in high yields (up to 94% yield). This method has notable advantages, such as simple and mild conditions, high yields, and good functional group tolerance.

Preparation and odor characteristics of nitriles derived from aldehydes

“…13 C NMR (75 MHz, CDCl 3 ): δ 19.3 (CH 3 C3), 22.3 (C5), 24.4 (C2), 30.3 (C3), 32.3 (CH 3 C7), 32.4 (CH 3 C7), 35.7 (C4), 45.7 (C6), 70.7 (C7), 118.7 (C1). The NMR data matched with those reported in the literature 26 …”

“…It is the most commonly used method to prepare nitriles by dehydration of the corresponding primary amides or aldoximes. Various approaches have been developed continuously, including transition metal medicated or catalyzed processes, such as Co(III), 16 Cu(II), 17 Pd(II), 18 Ti(IV), 19 Ce(IV), 20 Zn(II), 21 Fe (III), 22 and Ru(II), 23 and miscellaneous non‐metal reagents, such as NH 2 OH/Na 2 CO 3 /SO 2 F 2 , 24 organoselenium reagents, 25 O ‐benzoyl hydroxylamine, 26 [Et 2 NSF 2 ]BF 4 , 27 Ac 2 O, 28 Vilsmeier‐Haack reagent, 29 DCC, 30 Burgess Reagent, 31 (COCl) 2 /Ph 3 PO 32 or DMSO, 33 sulfuryl fluoride, 34 an oxoammonium salt with HMDS, 35 and O ‐benzenesulfonyl oxime catalyzed by a Brønsted acid 36 . In our recent work about the application of sulfoxide/oxalyl halide in organic synthesis, oxalyl chloride combined with a catalytic amount of DMSO was found to promote the dehydration of primary amides or aldoximes very efficiently with a clean conversion and almost quantitative yields in most cases 37 .…”

Microwave assisted one pot conversion of aromatic aldehydes to nitriles

“…In addition, FT-IR spectrum shows the presence of a strong peak at 1736 cm -1 along with sharp peaks in the range 3139 to 2863 cm -1 corresponding to aromatic and aliphatic C-H stretching vibration, respectively. Similar reaction conversion of aldehyde to nitrile through the oxime ester formation using o-benzoyl hydroxylamine has been reported [39].…”

Magnetically recoverable lanthanum hydroxide as an efficient catalyst for Aerobic Oxidative Conversions of primary alcohols to the nitriles

“…The formation of nitriles from aldehydes has been promoted with Ag nanoparticles and K 4 Fe(CN) 6 . Also, O ‐(4‐CF 3 ‐benzoyl)‐hydroxylamine as organic acid catalyst was reported for this transformation . These methods offer great improvements but purification and separation problem of these systems still needs to be improved.…”