Cyclopropenium-Activated Cyclodehydration of Diols
摘要:
The dehydrative cyclization of diols to cyclic ethers via cyclopropenium activation is described. Using 2,3-diphenylcyclopropene and methanesulfonic anhydride, a series of 1,4- and 1,5-diols are rapidly cyclized to furnish tetrahydrofurans and tetrahydropyrans in high yield. Eleven total substrates are shown, including a gram scale cyclization of a diterpene derivative.
Cyclopropenium-Activated Cyclodehydration of Diols
摘要:
The dehydrative cyclization of diols to cyclic ethers via cyclopropenium activation is described. Using 2,3-diphenylcyclopropene and methanesulfonic anhydride, a series of 1,4- and 1,5-diols are rapidly cyclized to furnish tetrahydrofurans and tetrahydropyrans in high yield. Eleven total substrates are shown, including a gram scale cyclization of a diterpene derivative.
One-Pot Sequential 1,4- and 1,2-Reductions of α,β-Unsaturated δ-Lactones to the Corresponding δ-Lactols with CuCl and NaBH4 in Methanol
作者:Yasunobu Matsumoto、Masahiro Yonaga
DOI:10.1055/s-0033-1340195
日期:——
An efficient, one-pot method for the highly chemoselective synthesis of δ-lactols fromα,β-unsaturatedδ-lactones using CuCl and NaBH4 in methanol was developed.
Rhodium‐Catalyzed Remote Borylation of Alkynes and Vinylboronates
作者:Minghao Zhang、Zheming Liu、Wanxiang Zhao
DOI:10.1002/anie.202215455
日期:2023.1.26
of internal alkynes and stericallyhindered tri- and tetra-substituted vinylboronates enabled by rhodium catalysis is reported. The 1,n-diboronate products can be converted to a variety of useful building blocks, biologically active molecules, and drugs via the selective manipulation of the two boryl groups in products including the regioselective cross coupling, oxidation, and amination.
The features of the present invention relate to compounds, compositions and methods useful for modulating the expression of vascular endothelial growth factor (VEGF), such as by the mechanism of RNA interference (RNAi). The compounds and compositions include iRNA agents that can be unmodified or chemically modified.
The features of the present invention relate to compounds, compositions and methods useful for modulating the expression of vascular endothelial growth factor (VEGF), such as by the mechanism of RNA interference (RNAi). The compounds and compositions include iRNA agents that can be unmodified or chemically-modified.