6640-25-1Relevant articles and documents
Silylium-Ion-Promoted (5+1) Cycloaddition of Aryl-Substituted Vinylcyclopropanes and Hydrosilanes Involving Aryl Migration
Bonetti, Vittorio,He, Tao,Klare, Hendrik F. T.,Oestreich, Martin,Wang, Guoqiang
supporting information, p. 12186 - 12191 (2020/05/22)
A transition-metal-free (5+1) cycloaddition of aryl-substituted vinylcyclopropanes (VCPs) and hydrosilanes to afford silacyclohexanes is reported. Catalytic amounts of the trityl cation initiate the reaction by hydride abstraction from the hydrosilane, and further progress of the reaction is maintained by self-regeneration of the silylium ions. The new reaction involves a [1,2] migration of an aryl group, eventually furnishing 4- rather than 3-aryl-substituted silacyclohexane derivatives as major products. Various control experiments and quantum-chemical calculations support a mechanistic picture where a silylium ion intramolecularly stabilized by a cyclopropane ring can either undergo a kinetically favored concerted [1,2] aryl migration/ring expansion or engage in a cyclopropane-to-cyclopropane rearrangement.
Mild Ring Contractions of Cyclobutanols to Cyclopropyl Ketones via Hypervalent Iodine Oxidation
Sun, Yan,Huang, Xin,Li, Xiaojin,Luo, Fan,Zhang, Lei,Chen, Mengyuan,Zheng, Shiya,Peng, Bo
supporting information, p. 1082 - 1087 (2018/01/27)
An iodine-mediated oxidative ring contraction of cyclobutanols has been developed. The reaction allows the synthesis of a wide range of aryl cyclopropyl ketones under mild and eco-friendly conditions. A variety of functional groups including aromatic or alkyl halides, ethers, esters, ketones, alkenes, and even aldehydes are nicely tolerated in the reaction. This is in contrast with traditional synthetic approaches for which poor functional group tolerance is often a problem. The practicality of the method is also highlighted by the tunability of iodine oxidation system. Specifically, combining the iodine(III) reagent with an appropriate base allows the reaction to accommodate a range of challenging electron-rich arene substrates. The facile scalability of this reaction is also exhibited herein. (Figure presented.).
Method for preparing 4-cypro methylene phenylboronic acid
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, (2017/08/31)
The invention discloses a method for preparing a 4-cypro methylene phenylboronic acid, and relates to the technical field of organic synthesis. The chlorobenzene is taken as the starting material, is subjected to a friedel-crafts reaction to generate 4-butanoyl chloride chlorobenzene, is subjected to a ring-closure reaction to generate 4-cypro formyl chlorobenzene, is subjected to a reduction reaction to generate 4-cypro methylene chlorobenzene, and is finally subjected to a Grignard boric acid reaction to generate the 4-cypro methylene phenylboronic acid. The cheap chlorobenzene, which is easy to get, is taken as the starting material, the preparation cost is remarkably lowered, the total molar yield of the product of 4-cypro methylene phenylboronic acid prepared through the 4-cypro methylene phenylboronic acid, the ring-closure reaction, the reduction reaction and the Grignard boric acid reaction is more than 35%, the production of the product is guaranteed on the basis of the low cost, and the method is suitable for industrial production.
