Synthesis of cyclic alkenyl ethers via intramolecular cyclization of O-alkynylbenzaldehydes. Importance of combination between CuI catalyst and DMF.
Synthesis of cyclic alkenyl ethers via intramolecular cyclization of O-alkynylbenzaldehydes. Importance of combination between CuI catalyst and DMF.
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DOI：
10.1021/jo049416b
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发表时间：
2004-06
期刊：
影响因子：
--
通讯作者：
N. Patil;Yoshinori Yamamoto
中科院分区：
文献类型：
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作者：
N. Patil;Yoshinori Yamamoto
本文提出了一种用Cu(I)催化邻炔基苯甲醛分子内环化合成环烯基醚的有效方法。对金属催化剂和溶剂的考察表明，碘化铜与DMF的组合是优选的催化体系。反应很可能是通过醇2亲核加成到o -炔基苯甲醛1生成相应的半缩醛，随后半缩氧亲核攻击到铜配位炔得到环化产物3。在所有情况下，反应以区域特异性的方式进行，通过6-内环环化导致六元内环产物。
An efficient and remarkably general method for the synthesis of cyclic alkenyl ethers via the Cu(I)-catalyzed intramolecular cyclization of O-alkynylbenzaldehydes has been developed. The survey of metal catalysts and solvents revealed that the combination of copper(I) iodide and DMF was the catalytic system of choice. The reaction most probably proceeds via the nucleophilic addition of alcohols 2 to O-alkynylbenzaldehydes 1 to generate the corresponding hemiacetals, and subsequent nucleophilic attack of the hemiacetal oxygen to the copper coordinated alkyne would give the annulation products 3. In all cases, the reaction proceeded in a regiospecific manner leading to the six-membered endocyclic products via 6-endo-dig cyclization.