Carbonylation of 1-Lithiobutadiene with Carbon Monoxide Followed by Intramolecular Acyllithiation of C═C Double Bond and Intermolecular Acylation with Acid Chloride: Scope, Applications, and Mechanistic Aspects
作者:Heng Li、Lantao Liu、Fei Zhao、Congyang Wang、Chao Wang、Qiuling Song、Wen-Xiong Zhang、Zhenfeng Xi
DOI:10.1021/jo300631d
日期:2012.5.18
gave rise to a butadienyl acyllithio intermediate, which underwent an immediate intramolecular acyllithiation of the C═C double bond, affording a lithio cyclopentadienyl enolate. The X-ray structural analysis of the enolate revealed a dimer connected with a “Li2O2” four-membered ring. Subsequent intermolecular acylation of this enolate with acid chlorides afforded β-keto-3-cyclopentenones, γ-keto-2-cyclopentenones
用CO一个1-锂-1,3-丁二烯衍生物的羰基化引起了丁二烯acyllithio中间体,其经历了C的直接分子内acyllithiation ═ C双键,从而获得锂代的环戊二烯基烯醇化物。烯醇化物的X射线结构分析显示与“ Li 2 O 2 ”有关的二聚体四元环。随后将该烯酸酯与酰氯的分子间酰化,得到β-酮-3-环戊烯酮,γ-酮-2-环戊烯酮或环戊二烯基酯衍生物。对原位生成的硫代环戊二烯烯基烯酸酯与各种酰氯的立体和区域选择性进行了研究和分析,表明上述产物的形成显着取决于丁二烯骨架上的取代基和酰氯的体积。
Hydride-induced cleavage of C–O bond in pyran ring of 2-pyranylidene carbene complexes: mechanism and synthetic application
作者:Qifeng Wang、Lantao Liu、Chen Lin、Hui Sun、Wen-Xiong Zhang、Zhenfeng Xi
DOI:10.1039/b918679b
日期:——
Hydride-induced cleavage of the CâO bond in the pyran ring followed by ring closure of unsaturated acylmetalates and reductive elimination was achieved.