Non-toxic cyanide sources and cyanating agents

Abstract

This review focuses on alternative cyanide sources and cyanating agents which are less hazardous than HCN or its salts.

Mild Palladium‐Catalyzed Cyanation of Unprotected 2‐Iodoglycals in Aqueous Media as Versatile Tool to Access Diverse C2‐Glycoanalogues

“…In terms of cyanating reagent, our choice turned to a non‐toxic, inexpensive cyanide source namely potassium ferrocyanide (K 4 [Fe(CN) 6 ]). This reagent attracted more and more attention thanks to its non‐hazardous properties and was already successfully used in many cyanation reactions . We started our methodology investigation on 2‐iodo‐ d ‐glucal 1 a , obtained in two steps from the commercially available peracetylated d ‐glucal (Table , for detailed study see SI) .…”

Catalytic Dehydrosulfurization of Thioamides to Nitriles by Gold Nanoparticles Supported on Carbon Nanotubes

“…Nitriles can be obtained through a number of synthetic methods including ammoxidation, cyanation of aryl precursors, or by displacement of leaving groups by nucleophilic cyanide ions . In the latter case, as the direct use of cyanides has obvious safety‐related drawbacks, non‐toxic cyanide sources as well as safer cyanation agents have now become available . Other routes leading to nitriles include the conversion of carboxylic acid, dehydration of amides or aldoximes, and oxidative coupling of alcohols to ammonia .…”

“…[2] In the latter case, as the direct use of cyanides has obvious safety-related drawbacks, non-toxic cyanide sources as well as safer cyanation agents have now become available. [3] Other routes leading to nitriles include the conversion of carboxylic acid, [4] dehydration of amides [5] or aldoximes, [6] and oxidative coupling of alcohols to ammonia. [7] Organic nitriles have also been prepared through dehydrosulfurization of thioamides but the latter transformation usually requires harsh conditions, [8] strong oxidizing agents, [9] toxic reagents [10] or the use of stoichiometric noble metals.…”

Bor‐Lewis‐Säure‐katalysierte Transferhydrocyanierung α‐ und α,β‐substituierter Styrole

“…Im industriellen Maßstab ist die übergangsmetallkatalysierte Hydrocyanierung von Alkenen unter Verwendung von Blausäure (HCN) die Methode der Wahl zur Herstellung von Nitrilen. Die erhebliche Giftigkeit von HCN [2] führte zu Bemühungen, weniger flüchtige Ersatzstoffe zu finden, [3] und Acetoncyanhydrin sowie Tr imethylsilylcyanid (TMSCN) werden dieser Anforderung in nickelkatalysierten Alkenhydrocyanierungen gerecht. 2 5.6 8 8C) in Forschungslaboratorien, trotz der Atomçkonomie seiner Addition an Mehrfachbindungen, weniger reizvoll.…”

“…[1] Im Gegenzug ist der Einsatz von gasfçrmigem HCN (Sdp.2 5.6 8 8C) in Forschungslaboratorien, trotz der Atomçkonomie seiner Addition an Mehrfachbindungen, weniger reizvoll. Die erhebliche Giftigkeit von HCN [2] führte zu Bemühungen, weniger flüchtige Ersatzstoffe zu finden, [3] und Acetoncyanhydrin sowie Tr imethylsilylcyanid (TMSCN) werden dieser Anforderung in nickelkatalysierten Alkenhydrocyanierungen gerecht. [4][5][6] Ein anderer Ansatz beruht auf Cobaltkatalyse,und diese Radikalreaktion nutzt festes Tosylcyanid (TsCN) mit PhSiH 3 als Quelle fürdas Wasserstoffatom.…”