A facile method for the synthesis of 2,3‐dihydro‐3‐methylidene‐1H‐isoindol‐1‐one and its derivatives carrying substituent(s) at C(5) and/or C(6) has been developed. The reaction of 2‐formylbenzonitrile (1a) with dimethyloxosulfonium methylide, generated by the treatment of trimethylsulfoxonium iodide with NaH in DMSO/THF at 0°, resulted in the formation of 2,3‐dihydro‐3‐methylidene‐1H‐isoindol‐1‐one
Highly Enantioselective Three-Component Povarov Reaction for Direct Construction of Azaspirocycles
作者:Nan-Fang Mo、Ying Zhang、Zheng-Hui Guan
DOI:10.1021/acs.orglett.2c02421
日期:2022.9.9
asymmetric organocatalyzed three-component Povarov reaction to construct azaspirocycles has been developed. A chiral phosphoric acid OCF-CPA bearing o-CF3-aryl on the H8–BINOL-framework is highly efficient in the reaction. The reaction was carried out under mind conditions for synthesis of a range of azaspirocycles in high yields and high to excellent enantioselectivities, thus expending the substrate
已经开发了一种用于构建氮杂螺环的不对称有机催化三组分波瓦罗夫反应。在 H 8 -BINOL 框架上带有o -CF 3 -芳基的手性磷酸OCF-CPA在反应中非常有效。该反应是在以高产率和高对映选择性合成一系列氮杂螺环的理想条件下进行的,从而扩大了传统波瓦罗夫反应的底物范围。
Enantioselective synthesis of spiro-<i>N</i>,<i>O</i>-ketals <i>via</i> iridium and Brønsted acid co-catalyzed asymmetric formal [4+2] cycloaddition
作者:Xiang-Qi Xie、Xingguang Li、Pei-Nian Liu
DOI:10.1039/d3cc05923e
日期:——
We present an iridium and Brønsted acid co-catalyzed enantioselective formal [4+2] cycloaddition reaction of cyclic enamides with 2-(1-hydroxyallyl)phenols. This method yields a wide range of N-unsubstituted spiro-N,O-ketals, with good efficiency (up to 94%) and excellent enantioselectivities (most >95% ee). The protocol features easy scale-up and facile product derivatization.
A silver-catalyzed formal [3 + 3] annulation of 3-methyleneisoindolin-1-one with alkynol for the synthesis of 1,5-dihydroindolizin-3(2H)-one derivatives is disclosed. The protocol allows practical synthesis of N-heterocyclic scaffolds with a broad scope of functional groups and could be efficiently scaled up to gram scale, which incarnates a potential application of this methodology. In addition, a range of chlorine anion substitution of alkenes can be constructed by adjusting the structure of the alkynol substrates with the use of TMSCl.