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.

Lewis酸介导的络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，络合控制的作用是通过一对孤对杂原子的配位来进行的，例如醛的氧原子和亚胺的氮原子与路易斯酸的配位，这被认为是σ-σ类型的络合。相反，我们发现某些炔基和烯基醛的化学和区域选择性反应是通过一对孤立的羰基化合物与C-C多键的σ-π-电子之间的π络合完成的。我们还发现，在相应的烷基环氧化物的共存下，炔基环氧化物的化学选择性开环是在Me_3Al介导的与炔基锂试剂的反应中实现的；这种有趣的化学选择性很可能是对环氧化物的氧原子和C-C三键的π-电子的n电子对的双齿络合的反映。

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)。

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)

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。

Asao, N., Kasahara, T., Yamamoto, Y.: "σ-πChelation-controlled chemoselective ring openings of epoxides"Tetrahedron Letters. 42. 7903-7905 (2001)

Asao, N.、Kasahara, T.、Yamamoto, Y.：“环氧化物的 σ-π 螯合控制的化学选择性开环”Tetrahedron Letters 42. 7903-7905 (2001)。