A synthetic strategy toward the cyclic addition of 2,2＇-dihydroxybiphenyl to terminal alkynes has been developed using Lewis acid TICl4 as catalyst. The reactions generated dibenzo[d,f][1,3]dioxepines derivatives in good yields with excellent regio-selectivity in the presence of catalytic amount of TICl4 under mild reaction conditions.
The immobilized nickel(II) on the organic-inorganic hybrid material was prepared and used as an effective catalyst for the Biginelli reaction.In the presence of the immobilized nickel catalyst,aromatic aldehydes reacted with ethyl acetoacetate and urea (or thiourea) smoothly to generate the corresponding Biginelli products in good to excellent yields without using any additive.The work-up procedure is very simple and practical.Furthermore,the silica-supported nickel(II) could be recovered and recycled for six consecutive trials without significant loss of its catalytic activity.
ZHANG LiYuanWANG ChuanHuZHOU LiLI PinHuaZHANG XiuLiWANG Lei
