Construction of heterocyclic compounds by use of α-diazophosphonates:: New one-pot syntheses of indoles and isocoumarins

[GRAPHICS] alpha-Diazophosphonates, which have extremely useful properties from a synthetic point of view, are disclosed as 1,1-ambiphilic one-carbon building blocks for one-pot construction of various heterocyclic compounds. They are easily prepared and have higher stability by the effect of the phosphoryl group than corresponding alpha-diazocarbonyl compounds. Using this synthon, we have developed a novel, mild, and efficient synthetic method of 2,3-disubstituted indoles and 3,4-disubstituted isocoumarins.