The reaction of 2-chloro-allyl acetate with sodium ethyl acetoacetate in the presence of a platinum-(0) complex gave furan derivatives. The key feature of this new platinum-catalyzed reaction is the nucleophilic substitution at the central carbon atom of π-allyl complexes. The regioselectivity of the nucleophilic attacks (central or terminal) is dependent on the pK a of the nucleophile. In addition, a labeling experiment revealed that a rapid syn-anti isomerization of the (π-allyl) platinum complexes occurs.

A New Platinum Complex Catalyzed Reaction Involving Nucleophilic Substitution at the Central Carbon Atom of the π-Allyl Ligand. -Stabilized carbon nucleophiles (II) undergo with various 2-chloroallyl acetates in the presence of a platinum(0) catalyst intermolecular cyclization to give furan derivatives. The key feature of this new type of catalytic reaction is the nucleophilic attack on the central carbon atom of π-allyl complexes. The regioselectivity of the nucleophilic attacks (central or terminal) is dependent on the pKa of the nucleophile. It is noteworthy that sodium diethyl malonate does not attack the central but the terminal carbon atom to afford 'classic' open chain products. -(KADOTA, JOJI; KOMORI, SHINJI; FUKUMOTO,