Diketene coupling reactions

An Al-acyl-(3-keto derivative has been prepared by reaction with a diketene equivalent and the tranj-N-cinnamoyl derivative by a Heck type coupling reaction. The A-fluoro derivative (3) is prepared by direct fluorination (eq 2). ... 

The final con und, 33, was prepared by a Grignard cross coupling reaction between diketene (39) and -butylmagnesium bromide in the presence of anhydrous cobalt iodide (30, 34). It is noteworthy that the Grignard reagent attacks the methylene carbon instead of the carbonyl carbon in the presence of cobalt iodide. 

BenZimidaZolones. This class of pigments derives its name from 5-aminobenzimidazolone/Pj5 -2J-< 7 which upon reaction with diketene or 2-hydtoxy-3-naphthoyl chloride leads to compounds which can be coupled with a variety of diazotized amines. 

The reaction may proceed in water, acetic acid, or any other organic solvent or mixture that is inert to diketene. This group also includes bifunctional coupling components of the bisacetoacetic diaminodiphenyl type ... 

The synthesis of the coupling component 5-acetoacetylaminobenzimidazolone (25) corresponds to the preparation of acetoacetarylides (Sec. 2.1.2) from 5-aminobenz-imidazolone by reaction with diketene or acetoacetic ester ... 

Cycloaddition of but-l-yne to the quinolone (58a) gave the head-to-tail [2 + 2] adduct (59). This approach was coupled with a ring-opening reaction to provide a synthesis of quinolones bearing a substituent at C-3. For example, the cycloadduct (60), obtained from the quinolone (58b) and 2-methylbut-3-yn-2-ol, was transformed into edulinine (61). The photocycloaddition of allene to the quinolone (58b) affords the two [2 + 2] adducts (62, 59.6%) and (63, 9.7%). Diketene has also been used in cycloadditions to quinolones (58c) and (58d). The addition process is selective in that cycloaddition to (58c) yields the adduct (64) whereas (58d) affords (65). In the latter case, the cycloadduct is accompanied by the rearranged product (66). These adducts were used in further chemical transformations. 

The action of a Zn/Cu couple on 1,3-dibromo ketones and secondary amides yields 2-dialkylamino-1,3-dioxolanes (451 equation 208). Fluorosulfonic peracid anhydride adds to trifluoroacetonitrile to give an amide acetal (452 equation 209). In the addition of (Z)-2-butene-l,4-diol to trichloroacetoni-trile, catalyzed by sodium, the 1,3-dioxepin (453 equation 210) is produced. Bicyclic amide acetals (454 equation 211) are byproducts in the reaction of lactim ethers with diketene. TTie methyl esters of perfluorinated carboxylic acids react with diethanolamine to afford bicyclic amide acetals (455 equation 212). Heating of maleic anilides (456 equation 213) with acetic acid anhydride/sodium acetate gives heterocyclic compounds (457) containing an amide acetal structure. ... 

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