Catalytic Availabilities of Lewis Acidic SnCl<sub>2</sub>: Ph<sub>3</sub>PAuCl-SnCl<sub>2</sub>Composite Catalyzed Successive<i>ortho</i>-Alkenylation/O-Alkenylation of Phenols Followed by Cyclization to 1-Benzopyrans
Ph3PAuCl and SnCl2, catalyzed the formation of 1-benzopyrans from phenols and phenylacetylene. The Ph3PAuCl–SnCl2 composite catalyzed reaction was presumed to proceed through the successive ortho-alkenylation and O-alkenylation of phenols with phenylacetylene followed by cyclization of the prepared ortho- and O-dialkenylated phenol derivatives. Conveniently, all reactions with Ph3PAuCl–SnCl2 composite
developed a B(C6F5)3catalyzedhydroarylation of terminalalkynes with various phenols at room temperature without adding any additives, leading to the synthesis of 2-gem-vinylphenols with good regio-selectivity. Those transformations featured a broad substrate scope with moderate yields. Mechanism studies indicated that those transformations proceeded through the activation of phenol by B(C6F5)3 with subsequent
A highly atom-efficient synthetic protocol for hydroarylation of terminal-aryl alkynes and styrene through the regioselective CC bond formation via the electrophilic addition of naphthols and substituted phenols has been developed using alumina-sulfuric acid as a heterogeneous supported solid acid catalyst. This methodology shows excellent regioselectivity and affords the desired product in good to
hydroarylation with naphthols and phenols in the presence of 10 mol% of gallium(III) chloride in refluxing toluene to afford the corresponding 2-vinylnaphthols and -phenols in good yields with high regioselectivity. Similarly, styrenes undergo hydroarylation with naphthols and phenols to provide substituted naphthols and phenols. arylations - arylacetylenes - gallium(III) chloride - phenols - addition reactions
transition metal-catalyzed reactions. Herein we have developed nickel-catalyzed synthesis of 3-aryl benzofurans from ortho-alkenyl phenols via intramolecular dehydrogenative coupling. Notably, simple O2 gas served as an oxidant, without using any sacrificial hydrogen acceptor. The strategy enabled the synthesis of 3-aryl benzofurans in good to excellent yields.
最近的研究集中在过渡金属催化的反应上。在此,我们开发了通过分子内脱氢偶联从邻-烯基酚中镍催化合成 3-芳基苯并呋喃。值得注意的是,简单的 O 2气体用作氧化剂,没有使用任何牺牲的氢受体。该策略能够以良好至优异的产率合成 3-芳基苯并呋喃。