Nucleophilic tele-substitution in 2-chloro-3-formylindoles via ring opening–ring closure
作者:Krystian Pluta、Kim V. Andersen、Frank Jensen、Jan Becher
DOI:10.1039/c39880001583
日期:——
2-Chloro-3-formylindoles give 5-azido-3-cyanoindoles on reaction with an excess of sodium azide in dimethylsulphoxide, as a result of a ring opening–ring closure with concomitant nucleophilic substitution at the 5-position in the indole ring; the X-ray crystal structure of the new 5-azidoindole has been determined.
The series of 3-monofunctionalized 2-oxindoles 2 were conveniently synthesized from reactions between anilide 1 and phenyliodine(III) diacetate (PIDA) through hypervalent iodine mediated C(sp(2))-C(sp(2)) bond formation followed by a subsequent deacylation reaction. This metal-free method, shown to provide direct access to an important oxindole intermediate, could be applied to the total synthesis of naturally occurring horsfiline.
Azide ring-opening-ring-closure reactions and tele-substitutions in vicinal azidopyrazole-, pyrrole- and indolecarboxaldehydes
作者:Jan Becher、Per Lauge Joergensen、Krystian Pluta、Niels J. Krake、Birgitte Falt-Hansen
DOI:10.1021/jo00033a039
日期:1992.3
5-Chloro-1-methylpyrazole-4-carboxaldehydes 1 react with excess sodium azide in dimethyl sulfoxide to produce a mixture of 1-azidomethyl-4-cyanopyrazoles 2 and 4-cyano-5-hydroxy-1-methylpyrazoles 3. Application of this reaction to the corresponding 5-chloro-1-phenylpyrazole-4-carboxaldehydes 5 gave 4-cyano-5-hydroxy-1-phenyl-pyrazoles 7 as the sole products in high yields. Likewise, 2-aryl-5-chloro-1-methylpyrrole-3,4-dicarboxaldehydes 9 rearranged to 2-aryl-4-cyano-5-hydroxy-1-methylpyrrole-3-carboxaldehydes 10 in high yields. In the indole series, treatment of 1-aryl-2-chloroindole-3-carboxaldehydes 11 with NaN3 yielded a mixture of 1-aryl-3-cyano-2(3H)-indolones 13 and 1-aryl-5-azido-3-cyanoindoles 12, both products resulting from a ring-opening-ring-closure reaction with concomitant nucleophilic tele-substitution at the 5-position of the indole ring.
PLUTA, KRYSTIAN;ANDERSEN, KIM V.;JENSEN, FRANK;BECHER, JAN, J. CHEM. SOC. CHEM. COMMUN.,(1988) N4, C. 1583-1584
作者:PLUTA, KRYSTIAN、ANDERSEN, KIM V.、JENSEN, FRANK、BECHER, JAN