O-chloroanil

Scheme 2.32 Formation of optically active a-hydroxyesters by reaction of acid chlorides with benzoylquinidine acting a catalytic chiral nucleophile, followed by [4+2]-cycloaddition with o-chloroanil.

SYNS l-AMINO-2-CHLOROBENZENE o-CHLO-RAMLINE o-CHLORO. NILINE o-CHLOROANIL-INE, Uquid o-CHLOROANILINE, soUd 2-CHLORO-BENZENAMINE (9CI) FAST T ELLOW GC BASE... 

In the case of the previously discussed [2]catenane 18 + shown in Figure 30, switching from the more stable translational isomer (which contains a TTF unit inside the tetracationic cyclophane) to a less stable one can be obtained not only by oxidation of the TTF unit, but also by addition of o-chloroanil. H NMR spectroscopy shows that o-chloroanil gives an adduct, presumably CT in nature, with the TTF unit which locks this unit alongside the cavity of the cyclophane. On addition of Na2S205 the adduct is destroyed and the original isomer with the TTF unit inside the cavity of the cyclophane is restored [59, 66[. 

Reaction of ketenylidene- or thioketenylidenetriphenylphosphoranes with a,P-unsaturated carbonyls, e.g. 2-benzylidene-l,3-indandione yields pyranones and thioxopyranones IQP Treatment of the same phosphoranes with o-chloroanil (tetrachloro-l,2-benzoquinone) yields 71Ketenylidenetriphenylphosphorane... 

At present one can only speculate about the nature of the intramolecular termination. However, macroradicals can be considered as strong electrophiles, comparable to u-chloro-anil or tetracyano ethene [12]. It is also known that ferrocene is oxidized by o-chloroanil or tetracyano ethene [13, 14]. Therefore it seems reasonable to assume termination via an intramolecular electron transfer step according to the following scheme ... 

C6CI11KO2, Potassium chloroanilate (a form), 39B, 80 C6CI11O2, Tetrachloro-o-benzoquinone, 44B, 104... 

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