Can I read A Convenient Synthesis of 4-Substituted 3-Ethoxy-5-methylisoxazoles by Palladium-catalyzed Coupling Reactions on EtoBox?

A Convenient Synthesis of 4-Substituted 3-Ethoxy-5-methylisoxazoles by Palladium-catalyzed Coupling Reactions by Hasse Kromann; Frank A Sløk; Tommy N Johansen; Povl Krogsgaard-Larsen is a Chemistry article available to read on EtoBox.

What is A Convenient Synthesis of 4-Substituted 3-Ethoxy-5-methylisoxazoles by Palladium-catalyzed Coupling Reactions about?

AbstractÐThe coupling reactions were performed using 3-ethoxy-4-iodo-5-methylisoxazole (4) as the key intermediate. Coupling of 4 under Suzuki±Miyaura or Stille conditions using Pd(PPh 3 ) 2 Cl 2 and arylboronic acids or aryltin analogues, respectively, gave 4-aryl substituted isoxazoles in yields ranging from 49% for the 3-pyridyl analogue 14, to 96% for the 4-pyridyl analogue 12. Under Heck reaction conditions using Pd(PPh 3 ) 2 Cl 2 and 4, analogues of 3-ethoxy-5-methylisoxazole containing vinylic or acetylenic groups in the 4-position were synthesized in yields ranging from 58 to 98%. 3-Ethoxy-5-methylisoxazol-4-ylmagnesium bromide ( ), prepared from 4 and isopropylmagnesium bromide, reacted smoothly with benzaldehyde or benzoyl chloride to give the desired 4-[hydroxy(phenyl)methyl] analogue 21 and 4-benzoyl-3-ethoxy-5-methylisoxazole ( ), respectively. Transmetallation of 19 with ZnCl 2 and subsequent treatment with Pd(PPh 3 ) 2 Cl 2 and 4-iodotoluene gave 3-ethoxy-5-methyl-4-(4-methylphenyl)isoxazole ( ) in 80% yield.

Who reads A Convenient Synthesis of 4-Substituted 3-Ethoxy-5-methylisoxazoles by Palladium-catalyzed Coupling Reactions?

Author

Hasse Kromann; Frank A Sløk; Tommy N Johansen; Povl Krogsgaard-Larsen

Publisher

Elsevier Science; Elsevier ; Elsevier Ltd.; Elsevier BV (ISSN 0040-4020)

Published

2001

Language

EN

Field

Chemistry (Physical Sciences)