Friedel-Crafts cyanation

Related to these intramolecular Friedel-Crafts cyclizations are the aluminum chloride and PPA catalyzed ring closures of 3-phenylpropyl iso- and thioiso-cyanates to 2H-2-benzazepin-l-ones and their -1-thiones respectively (79H(12)131i, 77JCS(Pl)2357). The method has also been applied to the cyclization of o-isocyanatodiphenylmethanes to 5,6-dihydro[6,e]azepin-6-ones (65HCA336). 

A few examples will show the importance of these reactions in synthetic organic chemistry. If X is an alkoxide ion, equation (1) describes the Williamson ether synthesis (2). If X is a cyanide ion, (1) describes a standard nitrile preparation (3). If X is an aromatic nucleus, and the departure of the leaving group is facilitated by A1C13, then (1) describes the Friedel-Crafts alkylation (4). With X as the cyanate ion, (1) describes the preparation of isocyanates (5) and if it is ammonia, (1) describes a common method of preparation of amines (6). In addition, nucleophilic transmethylation is a very... 

Alder, cyanation, allylation, Michael reaction, and Friedel-Crafts acylation). The same catalyst was also effective in three-component reactions such as Mannich-type reactions, Strecker, and quinoline-forming reactions. The polymer catalyst was recovered and reused many times without loss of activity (Eq. 31). 

The last two reactions are to be considered as cases of the normal Friedel-Crafts reaction, since the cyanate and mustard oil unite in the first phase with hydrochlorid add, forming an acid-chloride, which then reacts with the hydrocarbon with elimination of hydrochloric acid, e.g. -... 

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