Synlett, Table of Contents LETTER © Georg Thieme Verlag Stuttgart · New York Synthesis of 2H-Chromenes in Ionic Liquid Solvents George W. Kabalka*, Bollu Venkataiah, Bhaskar C. DasDepartments of Chemistry and Radiology, The University of Tennessee, Knoxville, TN 37996-1600, USAFax: +1(865)9742997; e-Mail: kabalka@utk.edu; Recommend Article Abstract Buy Article All articles of this category Abstract Vinylboronic acids react with o-hydroxyaryl aldehydes in room temperature ionic liquids in the presence of secondary amines to generate 2H-chromenes. Key Words ionic liquid - chromenes - Petasis reaction - boronic acid - green chemistry Full Text References References 1a Welton T. Chem. Rev. 1999, 99: 2071 1b Sheldon R. Chem. Commun. 2001, 2399 2 Freemantle M. Chem. Eng. News 2000, 78: 37 3a Laali KK. Gettwert VJ. J. Org. Chem. 2001, 66: 35 3b Park S. Kazalauskas R. J. Org. Chem. 2001, 66: 8395 3c Brown RA. Pollet P. McKoon E. Eckert CA. Liotta CL. Jessop PG. J. Am. Chem. Soc. 2001, 123: 1254 3d Carmichael AJ. Earle MJ. Holbrey JD. McCormac PB. Seddon KR. Org. Lett. 1999, 1: 997 4a Sengchantara ST. Wallace TW. Nat. Prod. Rep. 1986, 3: 465 4b Nicolaou KC. Pfefferkorn JA. Cao G.-Q. Angew. Chem. Int. Ed. 2000, 39: 734 4c Varma RS. Kabalka GW. Heterocycles 1985, 23: 139 5a Petasis NA. Akritopoulou I. Tetrahedron Lett. 1993, 34: 583 5b Petasis NA. Zavialov IA. J. Am. Chem. Soc. 1997, 119: 445 5c Petasis NA. Zavialov IA. J. Am. Chem. Soc. 1998, 120: 11798 5d Kabalka GW. Venkataiah B. Dong G. Tetrahedron Lett. 2004, 45: 729 6 Wang Q. Finn MG. Org. Lett. 2000, 2: 4063 7 Kabalka GW. Malladi RR. Chem. Commun. 2000, 2191 8 After extracting the product from the ionic liquid, the ionic liquid was diluted with acetone; a white solid precipitated and was removed by filtration. The acetone was evaporated under reduced pressure, and the ionic liquid was then reused.
