Carbonyl halides, reactions with ether, cyclic

Carbonyl halides, reactions with ethers, cyclic 21, 584... 

Blaser and Spencer used aroyl halides in place of aryl halides, with aroyl chlorides being of specific interest as ubiquitous, relatively cheap compounds ( Blaser reaction ) [24], This latter reaction is normally conducted in aromatic solvents phosphines are not used here as catalyst ligands since they fully inhibit the reaction. In the same way, benzoic acid anhydrides can be used as the aryl source in combination with PdCl2 and catalytic amounts of NaBr [79]. In this reaction, one of the arenes is used in the coupling reaction by elimination of CO, whereas the other benzoate serves as the base. The benzoic acid thus formed can easily be recycled into the anhydride. The use of aryl and vinyl triflates according to Cacchi [25] and Stille [26] extends the scope of the Heck coupling to carbonyl compounds phenol derivatives act via triflate functionalization as synthetic equivalents of the aryl halides. The arylation of cyclic alkenes [27], electron-rich vinyl ethers [28], and allylic alcohols [29] is accessible through Heck reactions. Allylic alcohols yield C-C-saturated carbonyl compounds (aldehydes) for mechanistic reasons (y9-H elimination), as exemplified in eq. (6). 

Cyclic vinyl ethers such a dihydropyran 86 form stable lithium derivatives 87 probably because isomerisation to structures like 85 is impossible. Reaction with electrophiles such as alkyl halides gives adducts, e.g. 88, and hydrolysis under very mild conditions reveals the carbonyl group19 89. 

Tri-n-hutylamine Reactions of carbonyl halides with cyclic ethers o>-Chloralkyl fluoroformates from carbonyl chloride fluoride... 

General Synthesis and Reactions.—Linear primary alcohols with at least seven carbon atoms are transformed into esters in high yield using copper oxide at temperatures above 170 C in the liquid phase. RusfCO) catalyses the conversion of an aldehyde, or an alcohol with the same number of carbon atoms, into an ester in the presence of diphenylacetylene. " The carbonylation of organic halides in the presence of cyclic ethers is catalysed by PhPdI(PPh3)2 , it provides a synthesis of halohydrin esters in reasonable yield. Cyanohydrin esters have been synthesized by the sodium borohydride reduction of acyl cyanides in the presence of tetra-n-butylammonium bromide. ... 

Group VI metal carbonyls catalyze the thermal or photochemical reaction of acyclic and cyclic ethers with acid halides to give esters (e.g., 4-chloropentylacetate, XLVIII) in good yields (Alper and Huang, 1973). The order of effectiveness for M(CO)g is Mo > W > Cr. Group V substituted... 

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