One-pot preparation of 2,5-disubstituted and 2,4,5-trisubstituted oxazoles from aromatic ketones with molecular iodine, oxone, and trifluoromethanesulfonic acid in nitriles
Alkyl aryl ketones were successfully converted into the corresponding 2,5-disubstituted and 2,4,5-trisubstituted oxazoles in good to moderate yields in a one-pot manner, utilizing iodine, Oxone®, and trifluoromethanesulfonic acid in nitriles under transition-metal-free conditions. The present method could be used for the preparation of Oxaprozin from benzyl phenyl ketone and succinonitrile. A possible
Iodoarene-catalyzed one-pot preparation of 2,4,5-trisubstituted oxazoles from alkyl aryl ketones with mCPBA in nitriles
作者:Yuhta Kawano、Hideo Togo
DOI:10.1016/j.tet.2009.05.003
日期:2009.8
aryliodonium I(III) species reacts with alkylaryl ketone to form β-keto aryliodonium species. This in turn, reacts with nitrile to form the corresponding oxazole. Iodoarene works as a catalyst. However, one equivalent of iodoarene is required because one equivalent of reactive aryliodonium I(III) species must be formed prior to the reaction with alkylaryl ketone. Then, by introducing an ionic liquid
Iodoarene-mediated one-pot preparation of 2,5-disubstituted and 2,4,5-trisubstituted oxazoles from alkyl aryl ketones with oxone in nitriles
作者:Yoshihide Ishiwata、Hideo Togo
DOI:10.1016/j.tet.2009.09.109
日期:2009.12
aryliodonium I(III) species reacts with alkylaryl ketone to generate β-keto iodonium species. Then, β-keto iodonium species reacts with nitrile to produce the corresponding oxazole. In principle, iodoarene works as a catalyst. However, 1 equiv of iodoarene is required because 1 equiv of reactive aryliodonium I(III) species must be formed before the reaction with alkylaryl ketone.
A direct and efficient method for the preparation of 2-substituted-5-aryloxazoles was realized by reaction of aryl methyl ketones with various nitriles in the presence of phenyliodine(III) triflate.
Metal-Free sp3 C–H Functionalization: PABS/I2-Promoted Synthesis of Polysubstituted Oxazole Derivatives from Arylethanones and 2-Amino-2-alkyl/arylacetic Acid
nonmetal-catalyzed process for the synthesis of polysubstituted oxazoles from inexpensive and readily available α-amino acids and methyl ketones is established. This reaction is proposed to achieve oxidative cleavage of C(sp3 )–Hbonds, followed by decarboxylation and annulation. The mild reaction conditions employed in both cases enable the tolerance of a wide range of functional groups as well as high reaction