β-Elimination of the isonitrile group in alkylation reactions of C–H acids activated by the isonitrile function
作者:Mikołaj Jawdosiuk、Maciej Umiński
DOI:10.1039/c39820000979
日期:——
During phase-transfer alkylation of the isonitriles R1R2CHNC with X–CH2–Y, where X is a leaving group and Y an electron withdrawing group, some of the alkylation products undergo β-elimination of the isonitrilefunction to yield R1R2CCHY.
在异氰酸酯R 1 R 2 CHNC用X–CH 2 –Y进行相转移烷基化的过程中,其中X是一个离去基团,Y是一个吸电子基团,一些烷基化产物会经历β-消除的异腈官能团,从而生成R 1 R 2 C CHY。
Palladium-catalyzed reactions of aryl iodides with trimethylsilylacetylenes and disubstituted alkynes: the synthesis of diarylacetylenes and triarylethylenes
trimethylsilylacetylene in the presence of 3 equiv. of sodiummethoxide and 5 mol% of Pd(PPh3)4 under refluxing methanol for 6 h gave diarylacetylene in good chemical yields. When the catalyst was replaced by Pd(dba)2 and 5 equiv. of aryl iodide were added under the same reaction conditions, triarylethylenes were obtained in 70–85% yields. Only the sterically hindered o-methoxyiodobenzene and 2-iodothiophene
methylheteroarenes (2-methylbenzothiophene, 2-methylbenzofuran, and 2-, 3-, or 4-methylpyridines) are used as nucleophiles. Application to enamine synthesis using DMF as an electrophile is also shown. The present system is effective for toluenes (4-phenyl-, 4-bromo-, 2-bromo-, and 4-chlorotoluenes) having lowreactivity.
here we took advantage of the photophysical properties of cercosporin, and used it as a metal-free photocatalyst to develop an unprecedented cercosporin-driven photocatalysis under mild conditions. Furthermore, the forming conditions and excited-state dynamics of radical anions of cercosporin have been systematically investigated. In particular, transient femtosecond absorption spectroscopy was employed
Facile synthesis of 1,2-thiobenzonitriles <i>via</i> Cu-catalyzed denitrogenative radical coupling reaction
作者:Yao Zhou、Ya Wang、Yixian Lou、Qiuling Song
DOI:10.1039/c9cc05099j
日期:——
A Cu-catalyzed synthesis of 1,2-thiobenzonitriles via oxidative C–N cleavage of 3-aminoindazoles followed by radical coupling with thiols is developed. A diverse array of 1,2-thiobenzonitriles were obtained in good yields with wide substrate scope. Notably, this is the first example of denitrogenative radical coupling with 3-aminoindazoles.