67838-03-3Relevant articles and documents
Radical Aryl Migration from Boron to Carbon
Daniliuc, Constantin G.,Mück-Lichtenfeld, Christian,Studer, Armido,Wang, Dinghai
supporting information, p. 9320 - 9326 (2021/07/19)
Radical aryl migration reactions represent a unique type of organic transformations that involve the intramolecular migration of an aryl group from a carbon or heteroatom to a C- or heteroatom-centered radical through a spirocyclic intermediate. Various elements, including N, O, Si, P, S, Sn, Ge, and Se, have been reported to participate in radical aryl migrations. However, radical aryl migration from a boron center has not been reported to date. In this communication, radical 1,5-aryl migration from boron to carbon in aryl boronate complexes is presented. C-radicals readily generated through radical addition onto alkenyl aryl boronate complexes are shown to engage in 1,5-aryl migration reactions to provide 4-aryl-alkylboronic esters. As boronate complexes can be generatedin situby the reaction of alkenylboronic acid esters with aryl lithium reagents, the aryl moiety is readily varied, providing access to a series of arylated products starting from the same alkenylboronic acid ester via divergent chemistry. Reactions proceed with high diastereoselectivity under mild conditions, and also the analogous 1,4-aryl shifts are feasible. The suggested mechanism is supported by DFT calculations.
Gold(i)-catalyzed dehydrogenative cycloisomerization of 1,5-enynes
Chen, Gen-Qiang,Fang, Wei,Wei, Yin,Tang, Xiang-Ying,Shi, Min
, p. 10799 - 10802 (2016/09/07)
The gold(i)-catalyzed dehydrogenative cycloisomerization of cyclopropane-tethered 1,5-enynes proceeded smoothly to give multisubstituted benzene derivatives in good to excellent yields. Synthetically important benzocyclobutenes can be produced in high yields in the presence of a gold(i) catalyst and DDQ. Furthermore, this reaction also works very well for non-cyclopropane tethered 1,5-enynes.
Synthesis of β,β-disubstituted γ-butyrolactones by chemo-selective oxidation of 1,4-diols and γ-hydroxy olefins with rucl3/NaIO4
Gao, Rong,Fan, Rong,Canney, Daniel J.
supporting information, p. 661 - 665 (2015/03/14)
Substituted γ-butyrolactones represent an important group of structural fragments commonly found in natural products, receptor ligands, and drug molecules. Interest in preparing a library of substituted γ-butyrolactones and finding that limited routes to β-substituted lactones exist, led to the development of an efficient approach for the synthesis of β,β-disubstituted γ-butyrolactones. Readily prepared substituted 1,4-diols and γ-hydroxy olefins were treated with the -RuCl3/NaIO4 oxidation system to provide the target β,β-disubstituted γ-butyrolactones in modest to good yields. The reaction goes through a lactol intermediate that was isolated and characterized for selected compounds. The approach supplies an efficient and versatile method for the synthesis of these important heterocyclic structures. Importantly, the present work is the first report that demonstrates the ability of RuCl3/NaIO4 to selectively oxidize primary hydroxyl groups in the presence of secondary alcohols to prepare lactones in good yields.
