Benzannelated cyclobutenediones

Liebeskind and co-workers have published a series of papers dealing with the chemistry of cyclobutenones and cyclobutene-diones. Thus an unprotected stannyl derivative bearing an amino function was reacted with an appropriate aryl iodide, leading in excellent yield to a pyrido-annelation product [64] (Scheme 4-23). The reaction of a monoprotected derivative with chlorocyclobutenones led to benzannelated cyclobutenediones [65], and stannyl derivatives of p-benzoquinone also underwent benzannelation when treated with these substrates [66]. Acylation of cyclobutenediones via stannyl derivatives has also been carried out [67], as has functionalization of cyclobutenones [68]. 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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