Heck-Type Processes Involving C-H Activation

Cascade reactions are often triggered when a syn-P-hydride elimination cannot take place, for example, in a bicycloalkyl- or neopentylpalladium intermediate. Such systems then seek an alternative reaction mode in particular, C-H activation often plays a major role [354, 355]. 

580 I 8 Cross-Coupling of Organyl Halides with Alkenes - The Heck Reaction X 

The formation of the interesting propellanes 234a,b with their hexaarylethane substructures from the hexacyclic hydrocarbon 235 with a central tetrasubstituted, but strained double bond, and iodobenzene or 1-iodonaphthalene under palladium catalysis, as reported by Dyker et al. [115], also proceeds via paUadacycle intermediates. 

2-tert-butyliodobenzene (242) with various aryl halides gave the benzoqrclobutene derivatives 243, the formation of which also involves an alkyl C-H activation [372e]. 

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