Microwave-assisted palladium-catalyzed cross-coupling reactions between pyranoid glycals and aryl bromides. Synthesis of 2′-deoxy C-aryl-β-glycopyranosides
作者:Ming Lei、Liang Gao、Jin-Song Yang
DOI:10.1016/j.tetlet.2009.06.116
日期:2009.9
perbenzylated pyranoid glycals were coupled with aryl bromides in the presence of 5% mol palladium(II) acetate in dimethylformamide to produce 2′,3′-unsaturated C-aryl-α-glycopyranosides in a rapid and stereospecific manner. The synthetic applicability of the method was further demonstrated by converting the resulting C-aryl glycosides to 2′-deoxy C-aryl-β-glycopyranosides through oxidation mediated by
Regioselective synthesis of 1,5-diarylpyrazole derivatives from hex-1-en-3-uloses
作者:Po-Yen Chen、Wei-Tsung Huang、Min-Tsang Hsieh、Chih-Shiang Chang、Hui-Chang Lin
DOI:10.1016/j.tet.2022.133070
日期:2022.11
1,5-diarylpyrazoles were synthesized by a two-step procedure startingfrom hex-1-en-3-uloses. The initial microwave-assisted oxidative Heck type C-glycosylation of hex-1-en-3-uloses with arylboronicacids in the presence of Pd(OAc)2 and DDQ afforded C-1 aryl enones. The resulting product further reacted with arylhydrazines in the presence of InCl3 and oxygen to give the 1,5-diarylpyrazoles in moderate
4-Conjugate addition of arylboronicacids to the glycal enones delivered 2-deoxy-α-aryl-C-glycosides in good yields. The reaction was catalyzed by palladium acetate in the presence of trifluoroacetic acid and 1,10-phenanthroline. A wide range of glycal enones derived from d-glucal, d-galactal, and d-rhamnal participated in the coupling reaction with different arylboronicacids smoothly. Different protecting
A wide range of aryl iodides bearing electron-donating and withdrawing groups underwent oxidative C-1 arylation with enones derived from glycals in the presence of Pd(OAc)2 and AgNO3 underligand-freeconditions. The developed methodology was successfully applied in the preparation of dapagliflozin analogues (SGLT-2 inhibitor).