From Highly Enantioselective Catalytic Reaction of 1,3-Diynes with Aldehydes to Facile Asymmetric Synthesis of Polycyclic Compounds

详细信息    查看全文

• 作者：Mark Turlington ; Yuhao Du ; Samuel G. Ostrum ; Vishaka Santosh ; Kathryne Wren ; Tony Lin ; Michal Sabat ; Lin Pu
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：August 3, 2011
• 年：2011
• 卷：133
• 期：30
• 页码：11780-11794
• 全文大小：1427K
• 年卷期：v.133,no.30(August 3, 2011)
• ISSN：1520-5126

文摘

(S)-1,1鈥?Binaphth-2-ol (BINOL) in combination with ZnEt₂, Ti(OⁱPr)₄, and biscyclohexylamine was found to catalyze the highly enantioselective (83鈥?5% ee) addition of various 1,3-diynes to aldehydes of diverse structures. This method provides a convenient pathway to generate a number of optically active dienediynes as the acyclic precursors to polycyclic compounds. The chiral dienediynes undergo highly chemoselective Pauson鈥揔hand (PK) cycloaddition in benzaldehyde by using [Rh(cod)Cl]₂ as the catalyst in the presence of rac-BINAP. High diastereoselectivity (up to >20:1) has also been achieved with the chiral dienediyne substrates containing a bulky substituent adjacent to the chiral center. In the presence of the Grubbs II catalyst, ring-closing enyne metathesis of the PK cycloaddition products led to the formation of the desired 5,5,7- and 5,5,8-fused tricyclic compounds. Further highly diastereoselective Diels鈥揂lder reaction of a 5,5,7-tricyclic compound with maleic anhydride produced a 5,5,7,6-polycyclic product. The asymmetric synthesis of polycyclic compounds from optically active dienediynes has established a novel and efficient synthetic route to the structural framework of many biologically significant molecules.