Palladium® salts tandem reactions

Felpin et al. developed a palladium-catalyzed tandem Heck reaction-reduction-cyclization synthesis of oxindoles (n=0) and dihydroquinolones (n= 1) using different 2-(2-nitrophenyl)aaylates (n=0) or 2-(2-nitrobenzyl)aaylates (n=l) and aryldiazonium salts 36 in good yield [15] (Scheme 6.7). However, a complementary approach was developed by the same group using diazonium salts 40 and substituted acrylates 41 to access a larger substitution pattern on the C3 position (Scheme 6.8). It is noteworthy that a different solvent was required and the charcoal had to be added after the Heck reaction. C3-unsubstituted, arylated, and alkylated dihydroquinolones 42 can be obtained efficiently using this protocol. 

A tandem four-component reaction of 2-bromobenzaldehyde (427), alkyne (428), amine (429), and diethylphosphite (430) catalyzed by a combination of palladium and copper salts, provided 1,2-dihydroisoquinolin-l-ylphosphonates (431) (Scheme 102). ... 

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