Synthesis of Allenes via Nickel-Catalyzed Cross-Coupling Reaction of Propargylic Bromides with Grignard Reagents
作者:Qinghan Li、Hanmou Gau
DOI:10.1055/s-0031-1290365
日期:2012.3
method for the synthesis of terminal allenes from cross-coupling of propargylic bromide with Grignardreagent. The reaction of propargylic bromide with 1.2 equivalents of Grignardreagent mediated by Ni(acac)2 (2 mol%) and Ph3P (4 mol%) in THF may produce terminal allenes in good yields and high regioselectivities at room temperature. allenes - nickel - propargylic bromide - Grignardreagent - cross-coupling
Benzyltriazoles have been catalytically oxidized by using CuI and tert-butyl hydroperoxide to yield phenyl(1H-1,2,3-triazol-4-yl)methanone derivatives in good yields at room temperature.
苄基三唑已通过使用 CuI 和叔丁基氢过氧化物催化氧化,在室温下以良好的产率得到苯基(1H-1,2,3-三唑-4-基)甲酮衍生物。
Palladium-Catalyzed Tandem Dimerization and Cyclization of Acetylenic Ketones: A Convenient Method for 3,3‘-Bifurans Using PdCl<sub>2</sub>(PPh<sub>3</sub>)<sub>2</sub>
Alkynones undergo tandem dimerization and cyclization in the presence of PdCl2(PPh3)2 and triethylamine in tetrahydrofuran at room temperature to give 3,3'-bifurans predominantly. Other palladiumcatalysts while under similar conditions, by rearrangement, lead to 2,5-disubstituted furans. This distinguished property of PdCl2(PPh3)2 has been attributed to the involvement of hydridopalladium halide.
of exploring new synthetic routes for obtaining this compound and analogues with improved bioactivity and lower toxicity. Herein, the chemical synthesis of carlina oxide analogues was developed. Their insecticidal activity was assessed on the vectors Musca domestica L. and Culex quinquefasciatus Say, and their cytotoxicity was evaluated on a human keratinocyte cell line (HaCaT). The compounds’ activity
A highlyregio- and enantioselective hydrosulfonylation using commercially available sodium sulfinates is reported, providing the first direct asymmetric rhodium-catalyzed hydrosulfonylation of allenes/alkynes to synthesize chiral allylic sulfones. Ligand screening studies demonstrated the indispensable role of the C1-symmetric P,N-ligand (Rax,S,S)-StackPhim for achieving both high regioselecitivity
据报道,使用市售亚磺酸钠进行高度区域和对映选择性氢磺酰化,提供了第一个直接不对称铑催化的丙二烯/炔烃氢磺酰化,以合成手性烯丙砜。配体筛选研究证明了C 1 -对称 P,N-配体 ( R ax , S , S )-StackPhim 对于实现高区域选择性 (>20:1) 和对映选择性 (高达 97% ee) 的不可或缺的作用。值得注意的是,操作简单的方法和温和的条件允许快速制备具有广泛官能团的手性烯丙基砜。此外,使用叔丁基二甲基甲硅烷氧基甲亚磺酸钠可以在受保护的羟甲基产物的简单转化后集体合成各种手性砜衍生物。