Copper catalyzed regioselective coupling of allylic halides and alkynes promoted by weak inorganic bases
作者:Lothar W. Bieber、Margarete F. da Silva
DOI:10.1016/j.tetlet.2007.08.010
日期:2007.10
Allylichalides and terminal alkynes couple under CuI catalysis in DMSO or DMF solution. In most cases, sodium carbonate or bicarbonate is sufficient to promote the reaction; less reactive alkynes require catalytic amounts of DBU. Bifunctional alkynes and halides can be reacted selectively according to the stoichiometry used. Trimethylsilyl, hydroxyl, ester and halide groups are tolerated in the alkyne
Radical Borylation/Cyclization Cascade of 1,6-Enynes for the Synthesis of Boron-Handled Hetero- and Carbocycles
作者:Shi-Chao Ren、Feng-Lian Zhang、Jing Qi、Yun-Shuai Huang、Ai-Qing Xu、Hong-Yi Yan、Yi-Feng Wang
DOI:10.1021/jacs.7b01889
日期:2017.5.3
construct boron-handled cyclic molecules was developed based on a radical borylation/cyclization cascade of 1,6-enynes. The process was initiated by the chemo- and regio-controlled addition of an N-heterocyclic carbene-boryl radical to an alkene or alkyne, followed by ring closure to afford boron-substituted cyclic skeletons. Further molecular transformations of the cyclic products to synthetically
synthesis of new core-Au/shell-CeO2 nanoparticles (Au@CeO2) using a redox-coprecipitation method, where the Au nanoparticles and the nanoporous shell of CeO2 are simultaneously formed in one step. The Au@CeO2catalyst enables the highly selective semihydrogenation of various alkynes at ambient temperature under additive-free conditions. The core-shellstructure plays a crucial role in providing the excellent
我们报告了一种使用氧化还原共沉淀法轻松合成新的核-Au/壳-CeO2 纳米颗粒(Au@CeO2),其中 Au 纳米颗粒和 CeO2 的纳米多孔壳在一个步骤中同时形成。Au@CeO2 催化剂能够在无添加剂的条件下在环境温度下实现各种炔烃的高选择性半氢化。核-壳结构通过最大化核-Au 和壳-CeO2 之间的界面位点,以异裂方式选择性解离 H2,从而为烯烃提供优异的选择性。
Copper-catalyzed enantioselective alkene carboetherification for the synthesis of saturated six-membered cyclic ethers
作者:Ilyas A. Berhane、Ameya S. Burde、Jonathan J. Kennedy-Ellis、Eva Zurek、Sherry R. Chemler
DOI:10.1039/d1cc03515k
日期:——
The enantioselective copper-catalyzed oxidative coupling of alkenols with styrenes for the construction of dihydropyrans, isochromans, pyrans and morpholines is reported. A concise formal synthesis of a σ1 receptor ligand using this alkene carboetherification methodology was demonstrated. Ligand, solvent and base all impact reaction efficiency. DFT transition state calculations are presented.
A variety of oximes were synthesized from the corresponding alcohols, alkyl halides, or alkyl sulfonates without using external oxidants. With this simple two-step procedure involving substitution with readily available TsNHOTBS and subsequent treatment with CsF, a range of oximes were prepared including the ones hardly preparable with conventional procedures.