Iodine catalyzed one-pot multi-component reaction to CF3-containing spiro[indene-2,3′-piperidine] derivatives
摘要:
In the presence of a catalytic amount of molecular iodine (0.1 equiv.), the one-pot multi-component reaction of ethyl trifluoroacetoacetate 1, indan-1,3-dione 2, ammonium acetate 3 and aromatic aldehyde 4 mainly gave the ethyl-6'-hydroxy-1,3-dioxo-2',4'-diary1-6'-(trifluoromethyl)-1,3-dihydrospiro[indene-2,3'-piperidinej-5'-carboxylate derivatives 5, along with the minor product 2-trifluoromethy12,3,4,5-tetrahydro-1H-indeno[1,2-b]pyridine derivatives 6. A plausible reaction mechanism for the formation of 5,6 was presented. The structures of compounds 5,6 were fully confirmed by H-1 NMR, F-19 NMR, MS, IR spectroscopies and elemental analysis or high resolution mass spectra (HRMS). Meanwhile, the representative 5a and 6h were further confirmed by XRD analysis. (C) 2011 Elsevier B.V. All rights reserved.