One-pot synthesis of 2-methylfurans from 3-(trimethylsilyl)propargyl acetates promoted by trimethylsilyl trifluoromethanesulfonate
作者:Danielle E. Sklar、Alex V. Helbling、Yiqi Liu、C. Wade Downey
DOI:10.1016/j.tetlet.2021.153424
日期:2021.12
In the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and triethylamine, 3-(trimethylsilyl)propargyl carboxylates undergo a one-pot alkylation-cyclization-desilylation reaction with ketones to produce 2-methylfurans. Alkylation at 0 °C in methylene chloride, followed by acid-catalyzed cyclization at room temperature, provides the furans in 52–86% yield. Cyclization and desilylation appear
在三氟甲磺酸三甲基甲硅烷基酯 (TMSOTf) 和三乙胺的存在下,羧酸 3-(三甲基甲硅烷基)炔丙基酯与酮进行一锅烷基化-环化-脱甲硅烷基化反应,生成 2-甲基呋喃。在 0 °C 下在二氯甲烷中烷基化,然后在室温下酸催化环化,以 52-86% 的产率提供呋喃。环化和脱甲硅烷基化似乎由在初始取代反应完成后将反应混合物暴露于水中而原位生成的三氟甲磺酸促进。
Copper-catalyzed propargylic [3+3] cycloaddition with 1<i>H</i>-pyrazol-5(4<i>H</i>)-ones: enantioselective access to optically active dihydropyrano[2,3-<i>c</i>]pyrazoles
作者:Ling Li、Zhen-Ting Liu、Xiang-Ping Hu
DOI:10.1039/c8cc05706k
日期:——
A copper-catalyzed asymmetric propargylic [3+3] cycloaddition with 1H-pyrazol-5(4H)-ones as C,O-bisnucleophiles through the desilylation-activated strategy has been developed. With the catalysis of Cu(OAc)2·H2O in combination with a chiral tridentate P,N,N-ligand, the reaction displayed a broad substrate scope, and thus provided a variety of chiral dihydropyrano[2,3-c]pyrazoles in high yields and with
通过去甲硅烷基化活化策略,开发了以1 H-吡唑-5(4 H)-为C,O-双亲核试剂的铜催化不对称炔丙基[3 + 3]环加成反应。Cu(OAc)2 ·H 2 O与手性三齿P,N,N-配体结合催化,反应显示出较宽的底物范围,从而提供了多种手性二氢吡喃[2,3- c ]吡唑类化合物的收率高(对映体选择性高达96%ee)。
Copper-catalyzed asymmetric propargylic etherification of oximes promoted by chiral tridentate P,N,N-ligand
作者:De-Quan Wei、Zhen-Ting Liu、Xue-Ming Wang、Chuan-Jin Hou、Xiang-Ping Hu
DOI:10.1016/j.tetlet.2019.151305
日期:2019.12
A copper-catalyzed asymmetric etherification of propargylic acetates with oximes as O-nucleophiles has been developed. The employment of a chiral tridentate P,N,N-ligand proved to be crucial for the success of the reaction. The reaction features a broad scope on either reaction partners and led to a variety of etherification products in good yields and enantioselectivities.