34782-55-3Relevant academic research and scientific papers
Bromomethyl Silicate: A Robust Methylene Transfer Reagent for Radical-Polar Crossover Cyclopropanation of Alkenes
Luo, Wenping,Fang, Yewen,Zhang, Li,Xu, Tianhang,Liu, Yongjun,Li, Yan,Jin, Xiaoping,Bao, Jiakan,Wu, Xiaodong,Zhang, Zongyong
supporting information, p. 1778 - 1781 (2020/03/11)
A general protocol for visible-light-induced cyclopropanation of alkenes was developed with bromomethyl silicate as a methylene transfer reagent, offering a robust tool for accessing highly valuable cyclopropanes. In addition to α-aryl or methyl-substituted Michael acceptors and styrene derivatives, the unactivated 1,1-dialkyl ethylenes were also shown to be viable substrates. Apart from realizing the cyclopropanation of terminal alkenes, the methyl transfer reaction has been further demonstrated to be amenable to the internal olefins. The photocatalytic cyclopropanation of 1,3-bis(1-arylethenyl)benzenes was also achieved, giving polycyclopropane derivatives in excellent yields. With late-stage cyclopropanation as the key strategy, the synthetic utility of this transformation was also demonstrated by the total synthesis of LG100268.
Method for synthesizing polysubstituted cyclopropane through photocatalysis of olefin cyclopropanation reaction
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Paragraph 0013; 0027-0029, (2020/04/29)
The invention discloses a method for synthesizing polysubstituted cyclopropane through photocatalysis of an olefin cyclopropanation reaction. The method comprises the following steps: adding a stirrer, polysubstituted olefin, Ir[dF(CF3)ppy]2(dtbbpy)PF6 and bromomethyl bis(catechol)silicate-18-crown ether-6-potassium into a reaction tube, vacuumizing, exchanging nitrogen, and injecting dimethyl sulfoxide; putting the reaction tube into blue light, stirring for 24 hours under the condition of illumination at room temperature, and extracting after the reaction is finished; and drying, carrying out column chromatography separation, and distilling to obtain polysubstituted cyclopropane. According to the invention, the method has the advantages of single reaction product, wide substrate universality, high functional group compatibility, mild reaction conditions and the like.
Visible-Light-Promoted Redox-Neutral Cyclopropanation Reactions of α-Substituted Vinylphosphonates and Other Michael Acceptors with Chloromethyl Silicate as Methylene Transfer Reagent
Guo, Ting,Zhang, Li,Liu, Xiaobo,Fang, Yewen,Jin, Xiaoping,Yang, Yi,Li, Yan,Chen, Bin,Ouyang, Minghui
supporting information, p. 4459 - 4463 (2018/09/14)
The alkene cyclopropanation with chloromethyl silicate as a methylene transfer reagent has been accomplished via visible-light-mediated redox-neutral catalysis. This method features broad functional group tolerance and mild conditions. In addition to α-substituted vinylphosphonates, a range of Michael acceptors including α,β-unsaturated acrylate, ketone, amide and sulfone are suitable substrates for this photocatalytic cyclopropanation. An application of this protocol to the cyclopropanation of estrone derivative is also presented. (Figure presented.).
