名称:
                                First construction of 12H-thiochromeno[2,3-b]quinolines and 5H-benzo[7,8]thiocino-[2,3-b]quinolines via intramolecular Friedel–Crafts reaction of Morita–Baylis–Hillman adducts
                             
                            
                                摘要:
                                An acid-promoted intramolecular Friedel Crafts reaction of the Morita-Baylis-Hillman adducts 3 derived from 2-arylthioquinolin-3-carbaldehydes 2 was investigated. Interestingly, promoted by sulfuric acid, the substrates with electron-donating groups on the aromatic ring gave six-membered fused-ring 12H-thiochromeno[2,3-b]quinolines 4 with good yields, while those with electron-withdrawing groups afforded eight-membered fused-ring 5H-benzo[7,8]thiocino[2,3-b]quinolines 5 in moderate yields. Using triflic acid instead of sulfuric acid, only products 4 could be obtained under the similar condition. (c) 2011 Elsevier Ltd. All rights reserved.