Green Synthesis Of Compounds Of Aromatic Alcohols And Asymmetric Synthesis

The addition of alkyl group to aldehydes and ketones is one of the most important methods in forming C-C bond, which may also produce sec-alcohol or tert-alcohol as valuable intermediate compounds applied in the synthsis of natural products. Performing the reaction via green method is one of the imperative tasks in organic chemistrys. At the same time, expanding the addition into asymmetric one with high enantioselectivity may lead to its siginificant application in synthesizing medicaments and biologically active compounds.This thesis reported the research about the green synthesis of homoallylic alcohol, the asymmetric allylation of aldehydes, the asymmetric addition of dialkylzinc to aldehyde and ketones. The concreate content is as below:1. In saturated NH₄CI solution, Zn/InCb (cat.)-mediated allylation of carbonyl compounds and allylic chloride could proceed smoothly to give the desired product in high yield. The regioselectivity and diastereoselectivity were also studied. Compared to the prior reports, the reaction can be carried out using allylic chloride instead of allylic bromide in the system, and it is a simple, efficient and environmentally benign synthesis method. Furthermore, crotyl chloride also gave excellent yields in this system. The reaction gave exclusively γ-adduct in most cases with medium diasteroselectivity.2. A series of chiral ligands containing hydroxyl and amido were derived from natural camphor, amino acid and tartaric acid, such as hydroxyl camphor sulfonylamide, sulfonamide alcohol, TADDOL, imine and its reductive product, C₂-symmetric camphor sulfonylamide and SALEN analogue. Employing these ligands into the allylation mediated by zinc, tin, indium, no acceptable enantioselectivity was obtained.3. Different substituents were introduced in the phenyl ring of hydroxyl camphor sulfonamide. The influences of substitution patterns, electronic property were studied in the diethylzinc to aldehyde, chiral ligand 3-16 was choosed as the best one (95% yield, 72% ee). Subsequently, varying the solvent, the temperature and the stoichiometry, the best condition was established and 83% ee was obtained in the system.