Development of the practical organic reactions based on the π-coordination of alkyne to Lewis acid

基于炔烃与路易斯酸π配位的实用有机反应的发展

• 批准号: 12554028
• 负责人: YAMAMOTO Yoshinori
• 金额: $ 8.83万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12554028/
• 关键词: Lewis acid; Chelation; Alkynes; Chemoselectivity; π-Coordination; Epoxides; 触媒

Lewis acid mediated chelatipn control is one of the most fundamental and efficient methodologies for effecting the selective carbon-carbon bond formation in modern organic synthesis. It is well accepted that the chelation-controlled feactions proceed through the coordination of a lone pair of heteroatoms, such as an oxygen of an aldehyde br a nitrogen atom of an imine, to a Lewis acid, which is recognized as a σ-σtype chelation. On the contrary, we found that chemo- and regioselective reactions of certain alkynyl and alkenyl aldehydes were accomplished through a σ-π chelation between a lone pair of the carbonyl compounds and π-electrons of the C-C multiple bond. We also found that the chemoselective ring opening of alkynyl epoxides in the co-existence of the corresponding alkyl epoxides is achieved in a Me_3Al mediated reaction with alkynyl lithium reagents; this interesting chemoselectivity is most probably a reflection of bidentate complexation to an n-electron pair of the oxygen atom of the epoxide and π-electrons of the C-C triple bond.

路易斯酸介导的螯合控制是现代有机合成中影响选择性碳-碳键形成的最基本和最有效的方法之一，人们普遍认为螯合控制的反应是通过一对孤对杂原子的配位进行的。作为醛的氧和亚胺的氮原子，形成路易斯酸，这被认为是σ-σ型螯合。相反，我们发现化学和某些炔基和烯基醛的区域选择性反应是通过羰基化合物与C-C多重键的π电子之间的σ-π螯合来完成的，我们还发现共存的炔基环氧化物的化学选择性开环。相应的烷基环氧化物是在 Me_3Al 介导的与炔基锂试剂的反应中实现的；化学选择性很可能反映了环氧化物氧原子的 n 电子对和 C-C 三键的 π 电子的双齿络合。

项目成果

Asao, N., Ohishi, T., Sato, K., Yamamoto, Y.: "σ-π Chelation-Controlled Stereoselective Hydrosilylation of Ketones"Journal of the American Chemical Society. 123. 6931-6932 (2001)

Asao, N.、Ohishi, T.、Sato, K.、Yamamoto, Y.：“σ-π 螯合控制的酮的立体选择性氢化硅烷化”美国化学会杂志 123. 6931-6932 (2001)。

N. Asao, T. Shimada, Y. Yamamoto: "Lewis Acid Catalyzed Stereoselective Carbosilylation. Intramolecular trans-Vinylsilylation and trans-Arylsilylation of Unactivated Alkynes"J. Am. Chem. Soc.. 123. 10899-10902 (2001)

N. Asao，T. Shimada，Y. Yamamoto：“路易斯酸催化的立体选择性碳硅烷化。未活化炔烃的分子内反式乙烯基硅烷化和反式芳基硅烷化”J。

N. Asao, T. Asano, Y. Yamamoto: "Do more electrophilic aldehydes/ketones exhibit higher reactivity toward nucleophiles in the presence of Lewis acids?"Angew. Chem., Int. Ed.. 40. 3206-3208 (2001)

N. Asao、T. Asano、Y. Yamamoto：“在路易斯酸存在下，更多的亲电醛/酮对亲核试剂表现出更高的反应性吗？”Angew。

E. Yoshikawa, M. Kasahara, N. Asao, Y. Yamamoto: "Lews acid-Catalyzed trans-Carbosilylation of Alkynes with Propargyl and Allenyltrimethylsilanes"Tetrahedron Lett.. 41. 4499-4502 (2000)

E. Yoshikawa、M. Kasahara、N. Asao、Y. Yamamoto：“路易斯酸催化的炔烃与丙炔基和烯基三甲基硅烷的反式碳甲硅烷基化”Tetrahedron Lett.. 41. 4499-4502 (2000)

T. Shimada, N. Asao, Y. Yamamoto: "Highly Diastereoselective Desymmetrizing Intramolecular Cyclization of Allylstannane with a Diketone Promoted by Lewis Acid or Transition Metal Complex"J. Organomet. Chem.. 624. 136-142 (2000)

T. Shimada、N. Asao、Y. Yamamoto：“路易斯酸或过渡金属络合物促进的二酮对烯丙基锡烷的高度非对映选择性去对称分子内环化”J。