Reaction on Mineral Supports

Alumina, silica, clay, and zeolites are increasingly bring used as acidic or basic supports in organic synthesis [3f, 13c, 33]. Several groups have reported improve- 

Several research groups have used solid supports such as alumina [38] and silica gel [39] to generate 1,3-dipoles, which undergo cycloadditions with alkene or al-kyne dipolarophiles to furnish five-membered heterocyclic compounds in a one-pot procedure. Use of microwaves has occasionally affected selectivity, changing the chemo or regioselectivity of the reactions compared with conventional heating. Several reports on [2+2] cycloadditions in dry media using solid supports have been published in the literature [40]. 

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