Acyl fluorides nitriles

H-Bond Acceptor (HBA) Acyl chlorides Acyl fluorides Hetero nitrogen aromatics Hetero oj gen aromatics Tertiary amides Tertiary amines Other nitriles Other nitros Isocyanates Peroxides Aldehydes Anhydrides Cyclo ketones Ahphatic ketones Esters Ethers Aromatic esters Aromatic nitriles Aromatic ethers Sulfones Sulfolanes... 

Condensation of an MSMA isonitrile with an aroylfluoride gives a salt which undergoes loss of trimethylsilyl fluoride to form a nitrile ylid. This transient species reacts with DMAD to form 2-aroyl pyrrole in high yield.162 Substitution of acyl chloride for acyl fluoride in the reaction affords only poor yields of adducts.465... 

Typically, oc,0-unsaturated esters, a,0-unsaturated aldehydes and a,0-unsaturated nitriles are poor acceptors for the Lewis acid catalyzed silylallylation procedure, but they are excellent acceptors for the complementary fluoride ion mediated allylation procedure (cf. Volume 4, Chapter 1.2, Section 1.2.2.1.7). Other suitable acceptors include 1,4-quinones,70 a,0-unsaturated acyl cyanides (162),718 silyl ot,0-enoates (163)71b and nitroalkenes (Scheme 26) 72 reduction (titanium(III) trichloride) of the intermediate nitronates arising from nitroalkene allylation affords y,8-enones (166). 

Acid fluorides are available from the corresponding chlorides or anhydrides using a new source of HF, pyridinium poly(hydrogen fluoride). Acyl nitriles are easily prepared in 33—89% yields from acid halides and cyanotrimethylsilane. ... 

M-Acyl-glycosylamines were the products from reactions of free sugars with nitriles in liquid hydrogen fluoride followed by an aqueous treatment. D-Ribose gave 1,2-siiS furanosylamines, e.q.. (9) as did D-arabinose and D-glucose. D-Mannose gave pyranosylamines, e.q.. (10), as did L-rhamnose. D-Xylose gave... 

Acylation of both aromatic and aliphatic compounds can be carried out with relative ease using acyl halides, acid anhydrides, ketenes, nitriles, amides, acids and esters in the presence of Friedel-Craft catalysts to give ketones. Similar substitution reactions with formic acid derivatives are therefore expected to yield the appropriate aldehydes. However, since the anhydride and acyl halides of formic acid, with the exception of formyl fluoride, are either not known or are not sufficiently stable to be used in Friedel-Crafts type acylation reactions, this objective cannot be fully realized. Table 1.1 compares the main ketone syntheses (based on acylating reagents) with the corresponding aldehyde syntheses (based on formylating reagents). 

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