A Germylene/Borane Lewis Pair and the Remarkable C=O Bond Cleavage Reaction toward Isocyanate and Ketone Molecules

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• 作者：Jiancheng Li ; Bin Li ; Rui Liu ; Liuyin Jiang ; Prof. Dr. Hongping Zhu ; Prof. Dr. Herbert W. Roesky ; Sayan Dutta ; Dr. Debasis Koley ; Prof. Weiping Liu and Qingsong Ye
• 刊名：Chemistry - A European Journal
• 出版年：2016
• 出版时间：October 4, 2016
• 年：2016
• 卷：22
• 期：41
• 页码：14499-14503
• 全文大小：1313K
• ISSN：1521-3765

文摘

A germylene/borane Lewis pair (2) was prepared from a 1,1-carboboration of amidinato phenylethynylgermylene (1) by B(C<sub>6sub>F<sub>5sub>)<sub>3sub>. Compound 2 reacted with iPrNCO and (4-MeOC<sub>6sub>H<sub>4sub>)C(O)Me, respectively, with cleavage of the C=O double bond. In the first instance, O and iPrNC insert separately into the Ge−B bond to yield a GeBC<sub>2sub>O-heterocycle (3) and a GeBC<sub>3sub>-heterocycle (4). In the second case (4-MeOC<sub>6sub>H<sub>4sub>)(Me)C inserts into the Ge−N bond of 2 while O is incorporated in the Ge−B bond to form a Ge-centered spiroheterocycle (5). The reaction of 2 with tBuNC to give 6, which has almost the same structure as 4, proved the formation of the isonitrile during transformation from 2 and iPrNCO to 3 and 4. The kinetic study of the reaction of 2 and iPrNCO gave evidence of proceeding through a GeBC<sub>3sub>O-heterocycle intermediate. In addition, a DFT study was performed to elucidate the reaction mechanism.