Gold-Catalyzed Addition of N-Hydroxy Heterocycles to Alkynes and Subsequent 3,3-Sigmatropic Rearrangement
摘要:
Gold-catalyzed intermolecular addition of hydroxybenzotriazole derivatives to alkynes at room temperature, gives vinyl ethers 3 in high yields and with excellent regioselectivity. Unlike many other vinyl ethers, 3 can easily be purified by regular silica-gel chromatography. On heating, 3,3-sigmatropic rearrangement of 3 gives access to highly functionalized benzotriazoles. This two-step sequence represents an efficient oxygen transfer protocol which incorporates a nucleophilic oxygen atom Into an alkyne group. Reaction of 3 with an electrophilic fluorinating reagent (Selectfluor) gives a fluorinated ketone regioselectively and in high yield.
Stable yet reactive cationic gold catalysts with carbon based counterions
作者:Xiaojun Zeng、Shiwen Liu、Bo Xu
DOI:10.1039/c6ra19064b
日期:——
Widely applicable cationic gold catalysts with a carbon based counterion.
具有碳基对离子的广泛适用的阳离子金催化剂。
Homogeneous and Nanoparticle Gold-Catalyzed Hydrothiocyanation of Haloalkynes
作者:Xiaojun Zeng、Bocheng Chen、Zhichao Lu、Gerald B. Hammond、Bo Xu
DOI:10.1021/acs.orglett.9b00728
日期:2019.4.19
homogeneous and heterogeneous nanoparticle gold-catalyzed addition of sulfur nucleophiles to alkynes was developed. More specifically, gold-catalyzed hydrothiocyanation of haloalkynes gave good yields and good stereoselectivity of vinyl thiocyanates. Furthermore, a sulfur-based gold catalyst (PPh3AuSCN) has shown a unique reactivity in gold-catalyzed reactions such as the cyclization of N-propargylic amides
Gold-Catalyzed Addition of <i>N</i>-Hydroxy Heterocycles to Alkynes and Subsequent 3,3-Sigmatropic Rearrangement
作者:Manish Kumar、Martin Scobie、Mark S. Mashuta、Gerald B. Hammond、Bo Xu
DOI:10.1021/ol4000789
日期:2013.2.15
Gold-catalyzed intermolecular addition of hydroxybenzotriazole derivatives to alkynes at room temperature, gives vinyl ethers 3 in high yields and with excellent regioselectivity. Unlike many other vinyl ethers, 3 can easily be purified by regular silica-gel chromatography. On heating, 3,3-sigmatropic rearrangement of 3 gives access to highly functionalized benzotriazoles. This two-step sequence represents an efficient oxygen transfer protocol which incorporates a nucleophilic oxygen atom Into an alkyne group. Reaction of 3 with an electrophilic fluorinating reagent (Selectfluor) gives a fluorinated ketone regioselectively and in high yield.