Lanthanoid(III) triflates as new glycosylation catalysts. Selective and efficient activation of 1-O-methoxyacetyl sugars
作者:Junji Inanaga、Yasuo Yokoyama、Takeshi Hanamoto
DOI:10.1016/s0040-4039(00)73563-5
日期:1993.4
The reactions of 1-O-methoxyacetyl sugars with alcohols or thiols were effectively promoted by a catalytic amount of lanthanoid(III) triflates such as Tb(OTf)3, Ho(OTf)3, Tm(OTf)3, and Yb(OTJ)3 to give the corresponding glycosides in good to excellent yields.
Catalytic O- and S-glycosylation of 1-hydroxy sugars
作者:Junji Lnanaga、Yasuo Yokoyama、Takeshi Hanamoto
DOI:10.1039/c39930001090
日期:——
O-Protected 1-hydroxysugars are effectively cross-coupled with a variety of alcohols and thiols to give the corresponding glycosides by using methoxyacetic acid and ytterbium(III) trifluoromethanesulfonate [Yb(OTf)3] as catalytic promoters.
Efficient Electrochemical<i>N</i>-Glycosylation of Silylated Pyrimidines with Protected Arylthioriboses in the Presence of a Catalytic Amount of NBS or Br<sub>2</sub>
Electrolysis of silylated pyrimidines with protected arylthioribose, in the presence of a catalytic amount of NBS or Br2 as a mediator in an undivided cell, gave the corresponding N-glycosides (nucleosides) in good yield.
Exposure of thiostannane to acetyl or methyl glycosides in the presence of a catalytic amount of Bu2Sn(OTf)2 provides thioglycosides in good yields. Selenoglycosidation is achieved in a like manner by use of selenostannane.
from 2,3,5-tri-O-benzyl-1-O-iodoacetyl-D-ribofuranose and trimethylsilylated nucleophiles such as 3β-cholestanyl trimethylsilyl ether and phenyl trimethylsilyl sulfide is efficiently promoted by tin(II) chloride under mild conditions. When allyltrimethylsilane, azidotrimethylsilane, etc., are used as nucleophiles, combined use of catalytic amounts of SnCl2 and SiCl4 also afforded the corresponding ribofuranosides