Synthesis of <i>o</i>-(Dimethylamino)aryl Ketones, Acridones, Acridinium Salts, and 1<i>H</i>-Indazoles by the Reaction of Hydrazones and Arynes
作者:Anton V. Dubrovskiy、Richard C. Larock
DOI:10.1021/jo302378w
日期:2012.12.21
A novel, efficient route to biologically and pharmaceutically important o-(dimethylamino)aryl ketones, acridones, acridinium salts, and 1H-indazoles has been developed starting from readily available hydrazones of aldehydes and o-(trimethylsilyl)aryl triflates. The reaction proceeds through arynes under mild conditions, tolerates a wide range of functional groups, and provides the final products in
carbon atoms. Furthermore, aliphatic aldehyde hydrazones and N-monosubstituted hydrazones which are unreactive in previously reported hydrazone perfluoroalkylation reactions now take part in the reaction under our reaction conditions to give satisfactory yield of products. Stern-Volmer quenching studies and spin-trapping experiments indicated that these reactions proceed by free radical addition of
Electrochemical synthesis of tetrazoles <i>via</i> metal- and oxidant-free [3 + 2] cycloaddition of azides with hydrazones
作者:Zenghui Ye、Feng Wang、Yong Li、Fengzhi Zhang
DOI:10.1039/c8gc02889c
日期:——
An unprecedented electrochemical [3 + 2] cycloaddition reaction for the synthesis of valuable tetrazoles was developed. Readily available azides and hydrazones were used as the starting materials under simple metal- and oxidant-free reaction conditions. Various functional groups are compatible with this green protocol which can be carried out on a gram-scale or in one pot easily.
, transition-metal-free, photocatalyst-free, and oxidant-free trifluoromethylation has been demonstrated. Triflicanhydride (Tf2O), being inexpensive and readily available, was chosen as the radical trifluoromethyl source. Thianthrene was used as a recyclable Tf2O-activating reagent, and a high-yielding and scalable trifluoromethylation reaction was achieved. Density functional theory and mechanistic
已经证明了一种有吸引力的、多功能的、操作简单的、可见光诱导的、无过渡金属、无光催化剂和无氧化剂的三氟甲基化。三氟甲磺酸酐 (Tf 2 O) 便宜且容易获得,被选为自由基三氟甲基源。噻蒽被用作可回收的 Tf 2 O 活化剂,实现了高产和可扩展的三氟甲基化反应。密度泛函理论和机理研究表明,可见光激发的自由基均裂过程参与了该反应,产生了关键的三氟甲基自由基中间体。