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چکیده
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The coupling reaction of a nitroalkane and the carbonyl group of an aldehyde or ketone in the presence of a base, is called Henry (nitroaldol) reaction. This reaction with no doubt, is one of the most effective methods for carbon-carbon bond formation in organic synthesis.1 The development and design of highly efficient and selective ligands are important factors in copper-catalyzed asymmetric Henry reactions.2 Preparation of chiral heterogeneous catalyst by immobilization of chiral ligands onto an inorganic mesoporous substrate such as SBA-15, has attracted a lot of attention in recent years.3 In this work, chiral amino oxazoline ligands were synthesized from chiral amino alcohols and cyanogen bromide.4 Next, by immobilization of them on mesoporous silica SBA-15, chiral heterogeneous ligands (OX-R-SBA-15) were synthesized and then characterized by using FT-IR, XRD, SEM, EDX, TGA, and BET-BJH techniques (Scheme 1). Finally, the obtained chiral heterogeneous ligands in the presence of copper salts were examined in enantioselective Henry reaction (Scheme 2). The resulting chiral β-nitroalcohols were obtained in high yields and good enantioselectivities
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