Peralkynylated Buta??1, 2, 3??Trienes: Exceptionally Low Rotational Barriers of Cumulenic C C Bonds in the Range of Those of Peptide C N Bonds

…, PD Jarowski, KN Houk, F Diederich

文献索引：Auffrant, Audrey; Jaun, Bernhard; Jarowski, Peter D.; Houk, Kendall N.; Diederich, Francois Chemistry - A European Journal, 2004 , vol. 10, # 12 p. 2906 - 2911

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被引用次数: 24

摘要

Abstract A variety of 1, 1, 4, 4-tetraal kynylbutatrienes and 1, 4-dialkynylbutatrienes was synthezized by dimerization of the corresponding gem-dibromoolefins. Both 1 H and 13 C NMR spectroscopy indicated that the di-and tetraalkynylated butatrienes are formed as a mixture of cis and trans isomers. Variable temperature NMR studies evidenced a facile cis– trans isomerization, thus preventing the separation of these isomers by gravity or high- ...