Construction of 2-Amino-2′-ketonyl Biaryls via Acid-Mediated Ring Opening of 9<i>H</i>-Fluoren-9-ols with Organic Azides
作者:Shan Yang、Biqiong Hong、Jia Feng、Zhenhua Gu
DOI:10.1021/acs.orglett.1c03484
日期:2021.12.3
cross-coupling between 9H-fluoren-9-ols and organicazides for the synthesis of steric hindered 2-amino-2′-ketonyl biaryls was reported. The reaction featured an acid-mediated azidation/ring-expansion/hydrolysis cascade, which formally realized the C–N bond coupling reaction via cleavage of a C–C single bond. This method was applicable to chiral helical structure to give bulky axially chiral biaryls with
报道了 9 H -fluoren-9-ols 和有机叠氮化物之间的直接交叉偶联,用于合成空间位阻 2-amino-2'-ketonyl biaryls。该反应具有酸介导的叠氮化/扩环/水解级联反应,通过C-C单键的断裂正式实现了C-N键偶联反应。该方法适用于手性螺旋结构,得到具有完全立体定向的大体积轴向手性联芳基化合物。
2,5-Dihydro-1H-1,2,4-triazol-2-yl radicals: Syntheses and properties
作者:Franz A. Neugebauer、Hans Fischer
DOI:10.1016/0040-4020(95)00730-v
日期:1995.11
A range of 2,5-dihydro-1H-1,2,4-triazol-2-yl radicals 2b-p has been prepared by dehydrogenation of the corresponding 4,5-dihydro-1H-1,2,4-triazoles 5b-p which have been synthesized using various methods. EPR, ENDOR and NMR studies have led to a complete analysis and full assignment of all hyperfine coupling constants. The pi-SOMO, having a node at the C(3) methine carbon, is mainly confined to the nitrogens of the five-membered ring, particularly to those of the hydrazyl moiety.