O,ω‐Unsaturated N‐tosyl alkoxyamines undergo unexpected RhIII‐catalyzed intramolecular cyclization by oxyamination to produce oxygen‐containing heterocycles. Mechanistic studies show that an aziridine intermediate seems to be responsible for the formation of the heterocycles, possibly via a RhV species.
Multi-Metal-Catalyzed Oxidative Radical Alkynylation with Terminal Alkynes: A New Strategy for C(sp<sup>3</sup>)–C(sp) Bond Formation
作者:Shan Tang、Yichang Liu、Xinlong Gao、Pan Wang、Pengfei Huang、Aiwen Lei
DOI:10.1021/jacs.8b02745
日期:2018.5.9
for C(sp3)-C(sp) cross-coupling with terminalalkynes has been developed by using a multi-metal-catalyzed reaction strategy. Alkyl radicals generated from different approaches are able to couple with terminalalkynes by judicious selection of the catalyst combination. This reaction protocol offers an efficient alternative approach for the synthesis of substituted alkynes from terminalalkynes besides
Gold(<scp>i</scp>)-catalyzed dehydrogenative cycloisomerization of 1,5-enynes
作者:Gen-Qiang Chen、Wei Fang、Yin Wei、Xiang-Ying Tang、Min Shi
DOI:10.1039/c6cc05423d
日期:——
Gold(I)-catalyzed dehydrogenative cycloisomeriaztion of cyclopropane tethered 1,5-enynes proceeded smoothly to give multisubstituted benzene derivatives in good to excellent yields. Synthetically important benzocyclobutenes can be produced in high yields in the...
作者:Dinghai Wang、Christian Mück-Lichtenfeld、Constantin G. Daniliuc、Armido Studer
DOI:10.1021/jacs.1c04217
日期:2021.6.30
engage in 1,5-aryl migration reactions to provide 4-aryl-alkylboronic esters. As boronate complexes can be generated in situ by the reaction of alkenylboronic acidesters with aryl lithium reagents, the aryl moiety is readily varied, providing access to a series of arylated products starting from the same alkenylboronic acidestervia divergent chemistry. Reactions proceed with high diastereoselectivity
自由基芳基迁移反应代表了一种独特类型的有机转化,涉及芳基通过螺环中间体从碳原子或杂原子向以 C 或杂原子为中心的基团的分子内迁移。据报道,包括 N、O、Si、P、S、Sn、Ge 和 Se 在内的各种元素参与了自由基芳基迁移。然而,迄今为止还没有报道从硼中心发生自由基芳基迁移。在这篇通讯中,介绍了芳基硼酸酯络合物中从硼到碳的自由基 1,5-芳基迁移。通过在烯基芳基硼酸酯络合物上进行自由基加成而容易产生的 C-自由基显示出参与 1,5-芳基迁移反应以提供 4-芳基-烷基硼酸酯。由于硼酸盐配合物可以原位生成通过烯基硼酸酯与芳基锂试剂的反应,芳基部分很容易改变,通过不同的化学反应,可以从相同的烯基硼酸酯开始获得一系列芳基化产物。反应在温和条件下以高非对映选择性进行,并且类似的 1,4-芳基位移也是可行的。DFT 计算支持建议的机制。
Enantioselective Copper‐Catalyzed Carboetherification of Unactivated Alkenes
作者:Michael T. Bovino、Timothy W. Liwosz、Nicole E. Kendel、Yan Miller、Nina Tyminska、Eva Zurek、Sherry R. Chemler
DOI:10.1002/anie.201402462
日期:2014.6.16
Chiral saturated oxygen heterocycles are important components of bioactive compounds. Cyclization of alcohols onto pendant alkenes is a direct route to their synthesis, but few catalytic enantioselective methods enabling cyclization onto unactivated alkenes exist. Herein reported is a highly efficient copper‐catalyzed cyclization of γ‐unsaturated pentenols which terminates in CC bond formation, a
手性饱和氧杂环是生物活性化合物的重要组成部分。醇在侧链烯烃上的环化是其合成的直接途径,但很少有催化对映选择性方法能够环化到未活化的烯烃上。本文报道了一种高效的铜催化 γ-不饱和戊烯醇环化反应,其终止于形成C C 键,这是一种净烯烃碳醚化。证明了分子内和分子间 C C 键的形成,从而产生功能化的手性四氢呋喃以及稠环和桥环氧杂双环产物。过渡态计算支持顺式氧化铜立体化学测定步骤。