One-Pot Double-Annulation Strategy for the Synthesis of Unusual Fused Bis-Heterocycles
作者:Shukree Abdul-Rashed、Georgios Alachouzos、William W. Brennessel、Alison J. Frontier
DOI:10.1021/acs.orglett.0c01351
日期:2020.6.5
A novel metal-free double-annulation cascade for the construction of unusual fused heterocyclic systems is described. This simple protocol enables the sequential assembly of two rings in one pot from two simple precursors. Acidic conditions promote the condensation and the intramolecular alkynyl Prins reaction of an enyne or arenyne alcohol with a cyclic hemiaminal to form a five-, six-, or seven-membered
Total Synthesis of Polyene Natural Product Dihydroxerulin by Mild Organocatalyzed Dehydrogenation of Alcohols
作者:Hexin Xie、Shilei Zhang、Hao Li、Xinshuai Zhang、Sihan Zhao、Zian Xu、Xixi Song、Xinhong Yu、Wei Wang
DOI:10.1002/chem.201103325
日期:2012.2.20
Polyene synthesis: An efficient approach to the total synthesis of polyene naturalproduct dihydroxrulin (1) is described. A novel, mild, direct organocatalytic IBX‐mediated dehydrogenation process of simple alcohols to enals has been developed, which serves as a key step in the synthesis (see scheme).
This invention is directed to compounds of the formula (I):
wherein one of R
6
, R
7
, R
8
and R
9
is
and X, R
1
to R
12
, m, n and o are as defined in the description, and pharmaceutically acceptable salts and/or esters thereof. The invention is also directed to pharmaceutical compositions containing such compounds, to a process for their preparation and to their use for the treatment and/or prevention of diseases which are modulated by PPARδ and/or PPARα agonists.
This invention is concerned with compounds of the formula I:
wherein one of R
5
, R
6
and R
7
is
and X
1
, X
2
, R
1
to R
12
, m, n and o are as defined in the description, and pharmaceutically acceptable salts and/or esters thereof. The invention further relates to pharmaceutical compositions containing such compounds, to a process for their preparation and to their use for the treatment and/or prevention of diseases which are modulated by PPARδ and/or PPARα agonists.
Tetrahydroxydiboron-Promoted Radical Addition of Alkynols
作者:Ze-Ying Sun、Sen Zhou、Kai Yang、Minjie Guo、Wentao Zhao、Xiangyang Tang、Guangwei Wang
DOI:10.1021/acs.orglett.0c02367
日期:2020.8.7
Tetrahydroxydiboron has previously been used as a borylation or reducing reagent in organic synthesis. Herein, we present a novel tetrahydroxydiboron-promoted radicaladdition of internal alkynes followed by intramolecular oxidation of alcohol through 1,5-hydrogen atom transfer. Preliminary mechanistic studies showed that the process might be initiated through N,N-dimethylformamide-assisted homolytic