Abstract
The diastereoselective two-step synthesis of heterotricyclic
systems is accomplished by regioselective cobalt-catalysed [4+2]-
and [4+2+2]-cycloaddition reactions
generating cyclohexa-1,4-diene and cycloocta-1,3,6-triene derivatives,
and a hetero-Diels-Alder reaction. Thus, a set
of selected cyclohexadienes and cyclooctatrienes were reacted with
cyclic 1,3-diones and formaldehyde in a Knoevenagel-hetero-Diels-Alder
multicomponent reaction to produce a variety of tricyclic products.
Key words
alkyne - catalysis - cobalt - cycloaddition - diene - multicomponent reaction - hetero-Diels-Alder
reaction
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7 The X-ray data have been deposited
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