Benzoyl chlorides, coupling reactions

The acylstannanes 874 and 875 are prepared by the reaction of acyl chlorides with (MciSnl - The symmetrical 1,2-diketones 877 can be prepared by the reaction of an excess of benzoyl chloride with (EtjSn) . Half of the benzoyl chloride is converted into the benzoyltin reagent 876, which is then coupled with the remaining benzoyl chloride under a CO atmosphere to afford the a-diketone 877[748], Triethyl phosphite is used as a ligand. 

Samarium iodide (Sml2) gives the same reaction. Benzoyl chloride was coupled to give benzil by subjecting it to ultrasound in the presence of Li wire 2 PhCOCl -I-... 

Cyclic triarylbismuth(III) compounds also undergo the Pd-catalyzed cross-coupling reaction with benzoyl chloride (Scheme 27) [42]. The exocyclic aryl group was selectively transferred to form 4-methylbenzophenone in good yield. Bismuth-containing products could not be isolated except for the cyclic bismuth compound possessing a SO2 moiety, for which cyclic bismuth chloride was isolated in 86% yield. 

Scheme 27 Cross-coupling reaction of cyclic triarylbismuth compounds with benzoyl chloride...

By contrast, for iodide 18 having the triple bond activated by a phenyl group, conversion to the cyclic organozinc species 25 occurred effectively and the latter could be efficiently functionalized, provided that traces of moisture were excluded by pre-treatment of zinc powder with Mel. The substituted benzylidene cyclopentanes 26 and 27 were respectively obtained after iodinolysis and palladium-catalyzed cross-coupling reaction with benzoyl chloride (equation 10). However, it could not be assessed whether the formation of organozinc 25 was attributable to an anionic or a radical cyclization pathway (or both) as, had iodide 26 been produced by a radical iodine atom-transfer, it would have been converted to 25 by reaction with metallic zinc due to the presence of the activating phenyl group21. 

Scheme 16 shows parallel syntheses of cyclic and acyclic amide compounds. Fluorous benzaldehydes were first subjected to reductive amination reactions. The resulting amines were then reacted with isocyanates to form substituted hydantoin rings 14 or with benzoyl chlorides to form amides 15. Purified F-sulfonates were used for palladium-catalyzed cross-coupling reactions to form corresponding biaryl 16 [31] and arylsulfide 17 [32] products, respectively. 

A similar reaction occurs with 2-pivaloylamino-4-oxopyrrolo[2,3-<7]pyrimidine. In this case the ratio of the 6-mercuri derivative to the 5-mercuri derivative was 10 1 <93H(36)1897>. Subsequent conversion of the mercuri compounds to the corresponding iodo derivatives provides the actual substrates for the palladium-catalyzed coupling reactions. Direct halogenation of the pyrrole ring has also been effected. In the only position available both chlorination (sulfuryl chloride) and bromination (NBS) have been achieved on the C-nucleoside (17 R = benzoylated ribose) (Equation (3)) <90JMC2750>. 

A study carried out by Kocienski and Lythgoe flrst demonstrated the trans selectivity of the Julia coupling process. The authors found the i uctive elimination could best be carried out with the acet-oxy or benzoyloxy sulfones. If the lithio sulfone derivative is used for addition to the carbonyl, the reaction can be worked up with acetic anhydride or benzoyl chloride to obtain the alkene precursor. In cases where enolization of the carbonyl is a complication, the magnesium derivative can frequently be used successfully. A modification of the reductive elimination was found to be most effective. Methanol, ethyl acetate/methanol or THF/methanol were the solvents of choice and a temperature of -20 C was effective at suppressing the undesired elimination of the acetoxy group to produce the vinyl sulfone. With these modifications of the original procedure, the ability of the reaction to produce dienes as well as rran.r-disubstituted alkenes was demonstrated, llie diastereoisomeric erythro- and threo-acetoxy sulfones could be separated and it was demonstrated that both isomers were converted to the rrans-alkene. It... 

The polymeric phenols 3 proved to be recyclable. A sample was reactivated for three reaction cycles using benzoyl chloride 2 as acylating agent. Coupling with benzylamine was used to determine the loading, which was found to be virtually identical for all three cycles [13]. 

If the coupling reaction of ethyl (4,6-diamino-3,5-dicyano-2-pyridyl)acetate with benzenediazonium chloride is performed in pyridine at 0°C, an oil results which, by refluxing in dimethylformamide, gives the cyclization product.64 In a one-pot reaction, 2-amino-3-benzoyl-5-cyano-4-phenylpyridine-6-acetonitrile, or the corresponding ethyl acetate, is coupled with benzenediazonium chloride in aqueous ethanolic sodium hydroxide, the mixture then left at room temperature to give 2-amino-3-benzoyl-5-imino-4,6-diphenyl-5,6-dihydropyrido[2,3-fi(]-pyridazine-8-carbonitrile (22a) or the ethyl 8-carboxylate 22b.65... 

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