Synthesis of (Z)-1-Aza-1,3-enynes by the cross-coupling of terminal alkynes with isocyanides catalyzed by rare-earth metal complexes.
Synthesis of (Z)-1-Aza-1,3-enynes by the cross-coupling of terminal alkynes with isocyanides catalyzed by rare-earth metal complexes.
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DOI：
10.1002/anie.200804306
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发表时间：
2008-12
影响因子：
--
通讯作者：
Wen‐Xiong Zhang;M. Nishiura;Z. Hou
中科院分区：
文献类型：
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作者：
Wen‐Xiong Zhang;M. Nishiura;Z. Hou
The 1, 1-insertion of isocyanides into the CÀH bond of terminal alkynes is a straightforward, atom economical route to conjugated 1-aza-1, 3-enynes (RC C-CH= NR’), which are compounds that are bifunctional (a basic nitrogen center found in the C= N bond and a CC bond) and are useful synthons in organic synthesis.[1–3] However, very few catalysts are known to promote the catalytic coupling reaction of isocyanides with terminal alkynes,[1] whereas stoichiometric insertion of isocyanides into a metal–acetylide bond is well documented.[2] In 2004, Eisen and co-workers reported the first catalytic coupling of isocyanides with terminal alkynes catalyzed by actinide metallocene complexes, which afforded the corresponding (E)-1-aza-1, 3-enynes as a major product together with alkyne oligomerization products and doubleinsertion products.[1a, d] Takaki and co-workers found that rareearth silylamides, such as [Ln {N (SiMe3) 2} 3](Ln= Y, La, Sm, Yb), could also catalyze the cross-coupling of isocyanides with terminal alkynes in the presence of amine additives to yield a mixture of E and Z isomers of 1-aza-1, 3-enynes.[1b, c] As far as we are aware, selective formation of (Z)-1-aza-1, 3-enynes in the reaction of terminal alkynes with isocyanides has not been reported previously. The search for new catalysts for the efficient and selective cross-coupling reaction of terminal alkynes and isocyanides is therefore of interest and importance.
