1,6-Conjugated Addition-Mediated [2+1] Annulation: Approach to Spiro[2.5]octa-4,7-dien-6-one
摘要:
A formal 1,6-conjugated addition-mediated [2+1] annulation to synthesize spiro[2.5]octa-4,7-dien-6-one with p-quinone methides and sulfur ylides has been described. This domino-type process was highly diastereoselective and exhibited good functional group tolerance and scalability without the use of metals and bases.
A ligand-free process of 1,6-conjugate reaction of para-quinonemethides with gem-diborylalkanes is reported using a copper catalyst. The reaction proceeded with good yield for a variety of para-quinonemethides and substituted gem-diborylalkanes under mild conditions.