Domino metathesis reactions cycloaddition

Within this chapter, two sections are devoted to rhodium and ruthenium. The two main procedures using rhodium are first, the formation of 1,3-dipoles from diazocompounds followed by a 1,3-dipolar cycloaddition [10] and second, hy-droformylation [11], The ruthenium-catalyzed domino reactions are mostly based on metathesis [12], with the overwhelming use of Grubbs I and Grubbs 11 catalysts. 

Grigg and coworkers developed bimetallic domino reactions such as the electro-chemically driven Pd/Cr Nozaki-Hiyama-Kishi reaction [69], the Pd/In Barbier-type allylation [70], Heck/Tsuji-Trost reaction/1,3 dipolar cycloaddition [71], the Heck reaction/metathesis [72], and several other processes [73-75]. A first example for an anion capture approach, which was performed on solid phase, is the reaction of 6/1-134 and 6/1-135 in the presence of CO and piperidine to give 6/1-136. Liberation from solid phase was achieved with HF, leading to 6/1-137 (Scheme 6/1.30) [76]. 

Enyne metathesis can also be combined with an intramolecular Diels-Alder reaction (IMDA) in a domino manner [35]. Reaction of the dienes 172 with the terminal alkynes 173 in the presence of the phosphine-free catalyst 4 at reflux temperature yielded the carbobicyclic products 174 preferentially via an exo-(E)-anti or endo-(2)-anti transition state for the [4- -2]-cycloaddition step, respectively (Scheme 2.60) [35a[. 

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