An efficient furan synthesis using heterogeneous catalysis
摘要:
A wide variety of 3-alkyne-1,2-diols have been found to undergo exceptionally clean 5-endo-dig cyclisations followed by dehydration at ambient temperature to give the corresponding furans in essentially quantitative yields when exposed to 10 mol % of 10%,w/w silver(1) nitrate absorbed on silica gel. (C) 2007 Elsevier Ltd. All rights reserved.
Synthesis of α-Hydroxyallenes by Copper-Catalyzed S<sub>N</sub>2′ Substitution of Propargylic Dioxolanones
作者:Xiaoping Tang、Simon Woodward、Norbert Krause
DOI:10.1002/ejoc.200900226
日期:2009.6
catalytic method for the synthesis of α-hydroxyallenes is described. Efficient SN2′ substitution of propargylic dioxolanones has been achieved with a copper(I)/P(OBu)3 catalyst using Grignardreagents as the nucleophiles. The reaction tolerates a wide variety of propargylic dioxolanones, the corresponding primary and secondary α-hydroxyallenes are obtained in good to excellent yields and excellent diastereoselectivity
5-Endo-dig iodocyclisations of alk-3-yn-1,2-diols 4, followed by in situ dehydration, lead to good yields of beta-iodofurans 5, which can subsequently be converted into a wide range of derivatives 6-13, using transition metal-catalysed coupling reactions or halogen-metal exchange.
An efficient furan synthesis using heterogeneous catalysis
作者:Simon J. Hayes、David W. Knight、Melanie D. Menzies、Mark O’Halloran、Wen-Fei Tan
DOI:10.1016/j.tetlet.2007.08.102
日期:2007.10
A wide variety of 3-alkyne-1,2-diols have been found to undergo exceptionally clean 5-endo-dig cyclisations followed by dehydration at ambient temperature to give the corresponding furans in essentially quantitative yields when exposed to 10 mol % of 10%,w/w silver(1) nitrate absorbed on silica gel. (C) 2007 Elsevier Ltd. All rights reserved.
Asymmetric dihydroxylation of enynes
作者:Kyu-Sung Jeong、Peter Sjö、K.Barry Sharpless
DOI:10.1016/s0040-4039(00)74797-6
日期:1992.6
Catalytic asymmetricdihydroxylations of 1,3-enynes were studied using 9-O-(9′-phenanthryl) dihydroquinidine (PHN-DHQD) 1 and 1,4-bis-(9-O-dihydroquinidine) phthalazine (DHQD2-PHAL) 2. Terminal olefins showed moderate (38-79% ee) and trans-disubstituted olefins high enantioselectivities (73 – 97% ee).