Practical alternatives for the synthesis of β-iodofurans by 5-endo-dig cyclisations of 3-alkyne-1,2-diols
摘要:
Iodocyclisations of 3-alkyne-1,2-diols, obtained from acetylides and a-hydroxy-ketones or esters, give generally excellent yields of beta -iodofurans by 5-endo-dig cyclisation followed by dehydration. (C) 2001 Elsevier Science Ltd. All rights reserved.
Leveraging the Micellar Effect: Gold-Catalyzed Dehydrative Cyclizations in Water at Room Temperature
作者:Stefan R. K. Minkler、Nicholas A. Isley、Daniel J. Lippincott、Norbert Krause、Bruce H. Lipshutz
DOI:10.1021/ol403402h
日期:2014.2.7
The first examples of gold-catalyzed cyclizations of diols and triols to the corresponding hetero- or spirocycles in an aqueous medium are presented. These reactions take place within nanomicelles, where the hydrophobic effect is operating, thereby driving the dehydrations, notwithstanding the surrounding water. By the addition of simple salts such as sodium chloride, reaction times and catalyst loadings
the gold‐catalyzed allene cycloisomerizations under aqueous micellar conditions is described. The polymers were prepared by ring‐opening cationic polymerization based on poly(2‐methyl‐2‐oxazoline) as hydrophilic segment and different hydrocarbon‐ or fluorocarbon‐based hydrophobic segments. The catalytic activity in the gold‐catalyzed allene cyclization is strongly dependent on the type of gold precursor
Gwerdziteli, Zhurnal Obshchei Khimii, 1948, vol. 18, p. 1187
作者:Gwerdziteli
DOI:——
日期:——
Cationic Gold(I)-Mediated Intramolecular Cyclization of 3-Alkyne-1,2-diols and 1-Amino-3-alkyn-2-ols: A Practical Route to Furans and Pyrroles
作者:Masahiro Egi、Kenji Azechi、Shuji Akai
DOI:10.1021/ol901942t
日期:2009.11.5
The intramolecular cyclizations of the 3-alkyne-1,2-diols and the 1-amino-3-alkyn-2-ols with a low catalyst loading (0.05-0.5 mol %) of (Ph3P)AuCl-AgNTf2 or (Ph3P)AuCl-AgOTf proceeded at room temperature to provide a variety of substituted furans and pyrroles in excellent yields (85-98% yields). This method is also fully applicable to the conversion of several dozen grams of the substrate using only 0.05 mol % each of the Au and Ag catalysts.
Sodium Chloride Catalyzed Regioselective Trifluoromethylthiolation of Furans
作者:Frank Glorius、Johannes Ernst、Lena Rakers
DOI:10.1055/s-0036-1588609
日期:——
Here, we report the catalytic trifluoromethylthiolation of furans employing sodium chloride as an inexpensive, abundant and ecologically friendly catalyst. The developed method exhibits perfect regioselectivity and a high functional group tolerance. Furthermore, the robustness of the newly developed method was determined by the additive-based Robustness Screen.