An efficient and ligand‐free palladium‐catalyzed arylation of benzofurans has been developed with N′ ‐acyl arylhydrazines as the coupling partners. This protocol features a wide functional‐group tolerance and highly regioselective products.
A rhodium-catalyzed efficient method for the synthesis of 2,3-dihydro-1H-indazoles is described. The reaction of arylhydrazines with olefins results in the corresponding 2,3-dihydro 1H-indazoles with exclusive regioselectivity via CâH bond activation. The utility of the methodology is illustrated by a rapid synthesis of 1H-indazoles under mild reaction conditions in half an hour.
A novel ligand-free palladium/copper-catalyzed Heck-type coupling reaction of alkenes and N′-acyl arylhydrazines has been developed by using air as the terminal oxidant. This protocol features wide functional group tolerance and produces highly chemoselective and regioselective products with good to excellent yields.
Compounds of the formula I, ##STR1## are NMDA antagonists and useful in the treatment and prevention of nervous system related pathological conditions resulting from overstimulation by excitatory amino acids. Methods for their preparation and pharmaceutical compositions containing them are also comprised according to the invention.
Synthesis of 1<i>H</i>-Indole-2,3-dicarboxylates via Rhodium-Catalyzed C–H Annulation of Arylhydrazines with Maleates
作者:Sheng Zhang、He Li、Yoshinori Yamamoto、Ming Bao
DOI:10.1021/acs.joc.0c01727
日期:2020.10.2
This work describes a one-step synthesis of 1H-indole-2,3-dicarboxylates through C–Hactivation. Rhodium-catalyzed tandem C–Hactivation and annulation of 2-acetyl-1-phenylhydrazines with maleates proceeded smoothly in the presence of additive NaOAc and oxidant Ag2CO3 and produced the corresponding indole derivatives, 1H-indole-2,3-dicarboxylates, in satisfactory to good yields. A variety of useful
这项工作描述了通过C–H活化的1 H-吲哚-2,3-二羧酸酯的一步合成。在添加剂NaOAc和氧化剂Ag 2 CO 3的存在下,铑催化的串联C–H活化和2-乙酰基-1-苯基肼与马来酸酯的环合反应顺利进行,并产生了相应的吲哚衍生物1 H-吲哚-2,3-二羧酸盐,令人满意的好收率。苯环上可耐受各种有用的官能团,包括卤素原子(F,Cl,Br和I)和甲氧羰基。