Addition Reactions of Arynes

2-Diallylbenzene (283) was obtained by the reaction of benzyne (252) with allyl chloride and allylstannane 282. Yamamoto et al. reported that Pd-catalyzed 

Carbostannation of arynes with alkynylstaimanes such as 286 as well as alkenyl-stannanes is catalyzed by Pd-iminophosphine (1-16) complex to give rise to 2-alkynylphenylstannane 287, which is convertible to a variety of 1,2-functionalized arenes such as 288 [88], 

Bis-silylation of benzyne with the disilane 289, catalyzed by the Pd complex of r-octyl isocyanide (XVII-6) gave the 1,2-disilylbenzene derivative 290 [89]. 

Benzyne can be carbonylated in the presence of allyl acetate to give 2-methyleneindanone 291 under atmospheric pressure of CO using DPPE as a ligand [90]. In this reaction, at first the 2-allylphenylpalladium 292 is generated. 

CO insertion affords the acylpalladium 293, and the following intramolecular insertion of alkene to the acylpalladium bond in 293 provides 294, which is converted to 291 by elimination. 

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