Magnesiacyclopentadienes as alkaline-earth metallacyclopentadienes: facile synthesis, structural characterization, and synthetic application.
Metallacyclopentadienes have attracted much attention as building blocks for synthetic chemistry as well as key intermediates in many metal-mediated or metal-catalyzed reactions. However, metallacyclopentadienes of the alkaline-earth metals have not been reported, to say nothing of their structures, reaction chemistry, and synthetic applications. In this work, the first series of magnesiacyclopentadienes, spiro-dilithio magnesiacyclopentadienes, and dimagnesiabutadiene were synthesized from 1,4-dilithio 1,3-butadienes. Single-crystal X-ray structural analysis of these magnesiacycles revealed unique structural characteristics and bonding modes. Their reaction chemistry and synthetic application were preliminarily studied and efficient access to amino cyclopentadienes was established through their reaction with thioformamides. Experimental and DFT calculations demonstrated that these magnesiacyclopentadienes could be regarded as bis(Grignard) reagents wherein the two Mg-C(sp(2)) bonds have a synergetic effect when reacting with substrates.
Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871 (China).
Junnian
J
Wei
Liang
L
Liu
Ming
M
Zhan
Ling
L
Xu
Wen-Xiong
WX
Zhang
Zhenfeng
Z
Xi
Grignard reagents; alkaline earth metals; lithium; magnesium; structure elucidation