Vinyl azides in heterocyclic synthesis. Part 6. Synthesis of isoquinolines by intramolecular aza-Wittig reaction
作者:Deirdre M. B. Hickey、A. Roderick MacKenzie、Christopher J. Moody、Charles W. Rees
DOI:10.1039/p19870000921
日期:——
Azidocinnamates containing ortho-carbonyl substituents are versatile intermediates for heterocyclic synthesis. Isoquinolines (8) and (9) are formed under mild neutral conditions by intramolecularaza-Wittigreactions of iminophosphoranes, readily derived from azides (1) and (2), respectively, with triethyl phosphite. The azafluoranthene (10) can also be prepared from the azide (3)via the isolable iminophosphoranes
A simple and efficient synthesis of isocoumarins and alkylidenephthalides from 3-(1-hydroxycarbethoxy/alkyl)phthalides with a DEAD/PPh<sub>3</sub>/TBHP system
作者:Sunita K. Gadakh、Arumugam Sudalai
DOI:10.1039/c4ra10372f
日期:——
to the synthesis of 3-carbethoxy-isocoumarins and 3-alkylidenephthalides is described. The methodology employs DEAD/PPh3/TBHP as the reagent system proceeding through unprecedented 1,2-shift intramolecular ring expansion or simple elimination depending upon substituents present on 3-substituted phthalides, with broader substrate scope. This strategy is amply demonstrated in the short synthesis of bioactive
Construction of Heterocyclic Compounds by Use of α-Diazophosphonates: New One-Pot Syntheses of Indoles and Isocoumarins
作者:Yoshinori Nakamura、Tatsuzo Ukita
DOI:10.1021/ol025916k
日期:2002.7.1
[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.
SAKAMOTO, TAKAO;KONDO, YOSHINORI;YAMANAKA, HIROSHI, HETEROCYCLES, 27,(1988) N, C. 453-456