Construction of Asymmetric Space and Catalytic Stereoselection with C_2-Symmetrical Molecules

C_2对称分子的不对称空间构建与催化立体选择

• 批准号: 06640765
• 负责人: YODA Hidemi
• 金额: $ 1.34万
• 依托单位: Shizuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640765/
• 关键词: Bisoxazoline; Chiral Ligand; Metal Complex; Amino Acid; Tartaric Acid; C_2-Imide; Nucleophilic Addition; Deoxygenation; オキサゾリン; Bisoxazoline; Chiral Ligand; Metal Complex; Amino Acid; Tartaric Acid; C_2-Imide; Nucleophilic Addition; Deoxygenation; オキサゾリン

1. According to my research scheme, asymmetric catalyst with the bisoxazoline ring system could be obtained from the coupling reaction of 2 equiv.of chiral amino alcohols with malononitrile-derived imidate and its activity as a chiral catalyst was investigated based on the alkylation of benzaldehyde with diethylzinc. Consequently, this reaction proceeded in about 40% ee.2. Consecutive treatment of C_2-symmetrical imides elaborated from L-tartaric acid with Grignard reagent and NaBH_4 afforded separable diastereomixture of chiral amide alcohols in high selectivity. Using these amide alcohols as catalysts, asymmetric alkylation with diethylzinc was investigated and the results are as follows ;(1) increasing a steric bulkiness of the N-substituent leads to an increase of the enantioselectivity.(2) maximally the catalyst recycles 18.8 times.(3) higher selectivity was obtained in the case of the catalyst with (4S)-configuration.(4) to enhance the selectivity ether is preferable over toluene as a solvent.Further, cyclic amides derived from D-arabinofuranose were also submitted to the same type of chiral catalytic reactions. It is interesting that no procedure for the asymmetric reactions with diethylzinc employing such as amide alcohols of cyclic amides as chiral catalysts has so far appeared.3. In addition to these reactions, asymmetric total syntheses of antibiotics, (-)-anisomycin and (+)-preussin were accomplished employing stereoselective nucleophilic addition and asymmetric deoxygenation of the hydroxy lactam intermediate elaborated from the same starting material, arabinofuranose.13EA09 : In summary, two new types of chiral ligands were prepared and investigated based on their catalytic activity and two antibiotic natural products were synthesized.

1。根据我的研究方案，可以从2等氨基醇与马诺诺硝基衍生的imiTAIDE的2等氨基醇的耦合反应中获得的非对称催化剂，并根据二甲基苯基苯基苯基苯基苯基的烷基化研究了其作为手性催化剂的活性。因此，该反应在约40％EE.2中进行。连续处理用Grignard试剂和NABH_4从L tart酸详细阐述的C_2合成Imides的连续处理，可在高选择性中提供手性酰胺酒精的可分离映异构体。使用这些酰胺醇作为催化剂，研究了不对称的烷基化，结果如下；（1）提高N-阳离子的空间体积的膨胀性会导致对映选择性的增加。（2）最大程度地提高了催化剂18.8次的速度。 （4s） - 配置。（4）为了提高选择性比甲苯比溶剂可比甲苯更可取。法术，从D-阿拉伯呋喃糖中得出的环状酰胺也被提交给相同类型的手掌催化反应。有趣的是，迄今为止出现了甲基津的不对称反应，二乙基的反应，例如手性催化剂的酰胺醇，迄今为止尚未出现。3。除了这些反应外，抗生素的不对称总合成，（ - ） - 雄霉素和（+） - 普雷塞蛋白是通过使用立体选择性的亲核添加和不对称的去对称性的综合级别的lig ligsssement obalinoferanose properabinofer.13 eyn.13 eys.13 eys.13 eys obal.13 eyper.13：in froper.13 eys.13：并根据其催化活性和两种抗生素天然产物进行了研究。