Cyano groups s. a. under

Cyano groups (s. a. under Replacement) retention 20, 124 suppl. 21 hydrogenation with - 22, 61 2-Cyano-O-heterocyclics... 

Cuprous cyanide (s. a. under EtMgBr) Replacement of bromine by cyano groups and chlorine Retention of configuration... 

Finally, the case of benzene derivatives having electron withdrawing substituents will be discussed. Experimental support for mein electron withdrawal by nitro and cyano groups has been found (3, (>, 20) in the photochemical solvolyses of nitrophenyl and cyanophenyl trityl ethers. For example, it is found that in the dark w-nitrophenyl trityl other (XLII) is essentially unreactive in 90% aqueous dioxanc while the para isomer (XLIII) solvolyzes smoothly this is in accord with ground-state, expectation, for p-nitrophenolate is a better departing anion than -nitropheiiolate. In contrast, on irradiation under the same conditions, m-nitrophcnyl trityl other solvolyzes rapidly to m-nitrophenol and tri-phenylcarbinol, as major products, while the para isomer s (XLIII) solvolysis is scarcely enhanced beyond experimental error. V similar... 

Freeman s group ° prepared a series of 5-amino-4-cyano-2-substituted oxazoles 517 from carboxylic acids and aminomalononitrile tosylate (AMNT) (Scheme 1.140). Presumably, AMNT is acylated by a carboxylic acid using DCC, which produces an intermediate A-acylamino nitrile 516 that is cyclized under the reaction conditions to yield 517. The yields of 517 are fair to excellent, and the reaction tolerates a wide variety of functional groups. This further extended the scope of their earlier work. ° Representative examples are shown in Table 1.35. 

A mixture of phenylthiomethyltrimethylsilane, p-methoxybenzaldehyde, and 0.1 eq. tetra- -butylammonium fluoride in THF allowed to react at room temp, for 15 h under argon, and treated with methanolic HCl - product. Y 66%. A number of functional groups (chloro, nitro, amino and cyano) remained intact. F.e. and with w-tolylthiomethyltrimethylsilane s. A. Hosomi et al., Chem. Pharm. Bull. 36, 3736-8 (1988). 

Wang, Liu, and coworkers developed a CuBr2-catalyzed synthesis of coumarins using a wide range of a-EWG-substituted ketene S,S-acetals, including a-aroyl, acetyl, cyano, ethoxycarbonyl groups with salicylaldehydes under very mild conditions [192] (Scheme 8.117). 

Sodium borohydride is sometimes used in conjunction with CeCl3 (Luche s reagent).70 The active reductants under these conditions are thought to be alkoxyborohydrides. Sodium cyanoborohydride is a useful derivative of sodium borohydride.71 The electron-attracting cyano substituent reduces reactivity and only iminium groups are rapidly reduced by this reagent. 

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