Gold(III) Porphyrin-Catalyzed Cycloisomerization of Allenones
摘要:
Gold(III) porphyrin-catalyzed cycloisomerization of allenones gave the corresponding furans in good to excellent yields (up to 98%) and with quantitative substrate conversions. By recovering the Au(III) catalyst, a recyclable catalytic system is developed with over 8300 product turnovers attained for the cycloisomerization of 1-phenyl-buta-2,3-dien-1-one. The versatility of the gold(Ill) porphyrin catalyst was exemplified by its application to the hydroamination and hydration of phenylacetylene in 73% and 87% yield, respectively.
Disclosed and exemplified are insecticidal and acaricidal optionally substituted furylbenzyl, thienylbenzyl, pyrazinylbenzyl, or pyridinzylbenzyl esters of the pyrethroid acids, novel pyrethroid alcohols and other intermediates, and compositions, a method of use and a process for preparation of the esters.
C−C-Bond Formation by the Palladium-Catalyzed Cycloisomerization/Dimerization of Terminal Allenyl Ketones: Selectivity and Mechanistic Aspects
作者:A. Stephen K. Hashmi、Thorsten L. Ruppert、Thomas Knöfel、Jan W. Bats
DOI:10.1021/jo970837l
日期:1997.10.1
conditions, besides the normal functional group tolerance known for palladium-catalyzed reactions, an interesting selectivity was observed with functional groups that are known to react either in palladium-catalyzed reactions or reactions catalyzed by other transition-metals. Thus aryl halides, terminal alkynes, 1,6-enynes, and alpha-allenic alcohols were tolerated. In the latter example the selective reaction
Synthesis and structure–activity relationship studies of 3-biaryl-8-oxabicyclo[3.2.1]octane-2-carboxylic acid methyl esters
作者:Lokman Torun、Bertha K. Madras、Peter C. Meltzer
DOI:10.1016/j.bmc.2012.01.053
日期:2012.4
Stille cross coupling protocols were utilized for the synthesis of 3-(biaryl)-8-oxabicyclo[3.2.1]oct-2-ene-2-carboxylic acid methyl esters, which furnished products in high yields where in some cases Suzuki coupling under the conditions utilized provided complex reaction mixture. Samarium iodide reduction of the resulting coupling products produced both of the 2β-carbomethoxy-3-biaryl-8-oxabicyclo[3
Stille 交叉偶联方案用于合成 3-(联芳基)-8-氧杂双环 [3.2.1] oct-2-ene-2-羧酸甲酯,其以高产率提供产品,其中在某些情况下铃木偶联所使用的条件提供了复杂的反应混合物。所得偶联产物的碘化钐还原生成 2β-carbomethoxy-3-biaryl-8-oxabicyclo[3.2.1] 辛烷非对映异构体和 2α-carbomethoxy-3-biaryl-8-oxabicyclo[3.2.1] 辛烷非对映异构体. 在合成的系列中,苯并噻吩取代的化合物表现出显着的抑制 WIN 35,438 的结合谱,对 DAT 与 SERT 的选择性为 177 倍。
Visible-Light-Promoted Arylation Reactions Photocatalyzed by Bismuth(III) Oxide
作者:Laura Buglioni、Paola Riente、Emilio Palomares、Miquel A. Pericàs
DOI:10.1002/ejoc.201701242
日期:2017.12.15
Bismuth(III) oxide has been successfully applied as a photocatalyst in the arylation of heteroarenes with diazonium salts. With a low catalyst loading (1 to 5 mol%), this cheap and non-toxic semiconductor could efficiently promote the formation of the aryl radical under visible light irradiation. The arylated products are obtained in moderate to good yields, and the the process admits straightforward
various substituents at the periphery of the macrocycle, are effective in catalyzing the light-induced direct arylation of heteroarenes and coumarins with diazoniumsalts. Mechanistic studies confirmed that the reaction operates by an oxidative quenching pathway of the porphyrin.
有机染料是一类很有前途的光氧化还原催化剂,为广泛应用的 Ru 和 Ir 配合物提供了一种有意义的替代品。我们发现具有调节物理化学性质的卟啉,通过在大环外围调整各种取代基,可有效催化杂芳烃和香豆素与重氮盐的光诱导直接芳基化。机理研究证实,该反应通过卟啉的氧化猝灭途径起作用。