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Dr. Albert Cabré Sergi Rafael Dr. Giuseppe Sciortino Prof. Gregori Ujaque Prof. Xavier Verdaguer Prof. Agustí Lledós Prof. Antoni Riera 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(19):7591-7597
The selective isomerization of strained heterocyclic compounds is an important tool in organic synthesis. An unprecedented regioselective isomerization of 2,2-disubstituted oxetanes into homoallylic alcohols is described. The use of tris(pentafluorophenyl)borane (B(C6F5)3), a commercially available Lewis acid was key to obtaining good yields and selectivities since other Lewis acids afforded mixtures of isomers and substantial polymerization. The reaction took place under exceptionally mild reaction conditions and very low catalyst loading (0.5 mol %). DFT calculations disclose the mechanistic features of the isomerization and account for the high selectivity displayed by the B(C6F5)3 catalyst. The synthetic applicability of the new reaction is demonstrated by the preparation of γ-chiral alcohols using iridium-catalyzed asymmetric hydrogenation. 相似文献
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《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(18):5132-5136
Palladium‐catalyzed regio‐, diastereo‐, and enantioselective allylic alkylation of β‐ketocarbonyls with Morita–Baylis–Hillman adducts has been developed using a spiroketal‐based diphosphine (SKP) as the ligand, thus affording a range of densely functionalized products bearing vicinal tertiary and all‐carbon quaternary stereodyad in high selectivities. The utility of the protocol was demonstrated by the facile synthesis of some complex molecules by simple product transformations. 相似文献
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Waqar Ahmed Sheng Zhang Xiaoqiang Yu Xiujuan Feng Yoshinori Yamamoto Ming Bao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(8):2517-2521
The cooperative catalysis of copper, silver, and Brønsted acid is presented as a new strategy for olefin functionalization. The catalytic direct carbohydroxylation of arylalkenes with allylic alcohols provided a straightforward and efficient approach for preparing 4,5‐unsaturated alcohols. Synthetically useful functional groups, such as Cl, Br, carbonyl, and chloromethyl, remained intact during the functionalization reaction. 相似文献