Cross-coupling reactions 3,/3 -substituted alkenylmetals

B.iv.a. p, P -Substituted Alkenybnetals. Carbometallation reactions of 1-alkynes, most notably carboalumination and carbocupration,t collectively provide a powerful route to the synthesis of /3,j8 -substituted alkenylmetals. The alkenylmetals generated in situ may be used directly for Pd- or Ni-catalyzed cross-coupling with aryl electrophiles (Protocol 1). One prototypical example of the carbometallation-cross-coupling tandem process is shown in Scheme... 

The synthesis of alkene-substituted arenes by cross-coupling can, in principle, be achieved either by the reaction of alkenylmetals with aryl halides and related electrophiles or by that of aryhnetals with alkenyl electrophiles. Eor the sake of simplicity, the former reaction is termed the alkenyl-aryl coupling, while the latter is termed the aryl-alkenyl coupling in this Handbook. Similar terms may be devised by linking the carbon groups of the organometal and organic electrophile with a dash in this order. 

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