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Camphor and its derivatives are important chiral substance, is an important organic chemical intermediates, mainly used in pharmaceutical, cosmetic and light industry being. Asymmetric synthesis of organic synthetic chemistry, and the most active areas of frontier in which the use of chiral catalysts in asymmetric synthesis synthetic strategy plays an important role. Because natural camphor is optically active natural products, low prices, rich source, with its chiral source asymmetric reactions has been a hot research topic, the study of their synthesis has important theoretical and practical value. This paper from natural D-camphor as raw material, sulfonation, chlorination, condensation, reduction reaction a new chiral ligand (Compound 96). First, the natural camphor and concentrated sulfuric acid in acetic anhydride for the reaction, since the reaction product formation is a natural process of crystallization, the study of factors affecting the crystallized to improve the reaction yield has a crucial role. In this paper feeding mode and the feed ratio on the yield, identified first with acetic anhydride was slowly added dropwise camphor dissolved in concentrated sulfuric acid and then the feed means and camphor sulfonate and sulfuric acid molar ratio of 1.0: 1.2 The best feed ratio, the reaction yield from the literature 46.6% to 68.3%, and the resultant camphor sulfonic acid also has a non-sticky, easy to handle and so on. Then, the camphor sulfonic acid and thionyl chloride in chloroform for chlorination reaction of camphor sulfonyl chloride, used in the process of this step instead of the usual PCl5 SOCl2 as a chlorinating agent, as in the preparation of the compound PCl5 , the reaction is severe, 0 ℃ or below shall be carried out. And post-processing is more troublesome, often local overheating, the chloride hydrolysis and emit toxic gases, with SOCl2 can overcome these shortcomings. And experimentally determined the optimal reaction feed ratio. Camphor sulfonyl chloride and then the chiral amino alcohol condensation reaction of an amide (Compound 95), and to determine the optimal reaction molar ratio. Product is then reduced to a novel chiral ligand (Compound 96), the choice of relatively moderate reactivity NaBH4, and to determine the optimal dosage of the. When the feed ratio n (reactant): n (NaBH4) = 2, the reaction yield was 70.6%. The successful synthesis of chiral ligands (compound 96) after its oxidation of sulfide in the chiral sulfoxide enantioselective catalytic reactions were studied, won 65.2 percent of the chemical yield and 35.2? enantioselectivity, showing moderate activity and less than ideal asymmetric induction. In the naturally occurring chiral source, L-amino acid is very important class, wherein the L-glutamic acid used widely, from L-glutamic acid can be obtained by dehydration under heating L-pyroglutamic acid. L-pyroglutamic acid is not only cheap and readily available chiral material, and a nitrogen-containing heterocyclic ring having five yuan reactive groups and two structural features. Using L-pyroglutamic acid is widely used as a chiral source of biologically active natural and non-natural synthesis of chiral substances, e.g. chiral synthesis of pharmaceutical, pesticide product development, it is in the asymmetric synthesis potential will continue to be developed. We focus on glutamate-derived chiral ligand (Compound 103, 104) have been tried synthetic successful synthesis of Compound 99, and in the subsequent reaction, since the synthesis of a Grignard reagent repeated attempts fail, in the end has not been target product.
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