Pyridinium phosphates amines

Other allylic substrates have become useful allylic sources to synthesize palladium(ll) 77 -allyls by oxidative addition to Pd(0) complexes. Allylic nitrogen derivatives such as ammonium, pyridinium, iminium salts,and other derivatives have been used. Allyl phosphonium salts and allyl phosphates also lead to 7 -allylic palladium(n) complexes. In these examples, a bidentate ligand is present in the reaction medium either coordinated to the Pd(0) precursor or added to the reaction mixture, so the amine, pyridine, imine, or phosphine byproduct does not remain coordinated to the metal in the final rf-MyX complex. 

Similarly, the methiodide was reacted with diethyl (2,2,2-trichloro-ethoxycarbonyl)aminomalonate as a nucleophile to give 118, which was then converted to the amine 119 by deprotection of the 2,2,2-trichloroethoxy-carbonyl group with zinc and potassium dihydrogen phosphate. Dehydrative cyclization of 119 to the azepinoindole 120 was achieved by heating 119 in the presence of a catalytic amount of pyridinium p-toluenesulfonate in dichloromethane. Hydrolysis of 120 with potassium hydroxide in methanol yielded the malonic acid derivative which was then readily decarboxylated on heating in aqueous ethanol to accomplish total syntheses of ( )-cis- and ( )-tranj-clavicipitic acid (84,85) in aratio 3 2 (Scheme 18) (57). 

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