Tandem Dehydrogenation/Oxidation/Oxidative Cyclization Approach to Wrightiadione and Its Derivatives
摘要:
Wrightiadione contains a unique tetracyclic isoflavone moiety and has been shown to exhibit a broad range of biological activities. An efficient and Straightforward synthetic method for generating the molecular complexity,of wrightiadione was developed, through three-step tandem dehydrogenation/oxidation/oxidative cyclization reactions with a Pd/Cu. catalytic system. This Unprecedented one-pot route utilizes a broad: range of substrates, providing a convenient and powerful synthetic tool for accessing naturally occurring tetracyclic isoflavone wrightiadione and its nitrogen-containing derivatives.
Hetero-ring lithiation of N-methyl-4-quinolone and N-methylquinoline-4-thione
摘要:
Lithiation of 1-methyl-4-quinolone and 1-methylquinoline-4-thione with lithium diisopropylamide (LDA) at -78-degrees-C takes place at C-2. The resulting lithio-species react with a variety of electrophiles to give 2-substituted-4-quinolones and -quinolines-4-thiones respectively. 1-Methylquinoline-4-thione is easily converted into 1-methyl-4-quinolone in protic solution.