An Expeditious Route to<i>trans</i>-Configured Tetrahydrothiophenes Enabled by Fe(OTf)<sub>3</sub>-Catalyzed [3+2] Cycloaddition of Donor-Acceptor Cyclopropanes with Thionoesters
A synthetic route to trans‐configured tetrahydrothiophenes (THTs) through Fe(OTf)3‐promoted [3+2] cycloaddition of donor–acceptor cyclopropanes with thionoesters was developed. The cycloaddition proceeded in high yield with high diastereoselectivity, affording transient α‐alkoxy THTs. Not only aromatic and aliphatic thionoesters, but also thionolactone were applicable to the present iron catalysis
(3 + 2)-Cycloaddition of Donor–Acceptor Cyclopropanes with Selenocyanate: Synthesis of Dihydroselenophenes and Selenophenes
作者:Anu Jacob、Peter G. Jones、Daniel B. Werz
DOI:10.1021/acs.orglett.0c03329
日期:2020.11.6
We present a Lewis-acid-catalyzed (3 + 2)-cycloaddition of donor–acceptor cyclopropanes and selenocyanate (as its tetramethylammonium salt) for the synthesis of dihydroselenophenes. The transformation proceeded with moderate to excellent yields and showed a high functional group tolerance. Further oxidation using DDQ delivered selenophenes.
The homologous conjugate addition of thiols to electron-deficient cyclopropanes catalyzed by a calcium(II) complex
作者:Caroline M. Braun、Alyssa M. Shema、Callie C. Dulin、Kristine A. Nolin
DOI:10.1016/j.tetlet.2013.08.102
日期:2013.10
of γ-sulfanyl malonates was achieved through the addition of thiols to electron deficient cyclopropanes. These reactions are catalyzed by calcium acetylacetonate, Ca(acac)2. A variety of electron rich and electron deficient thiols were added without the need for prior activation or exogenous base. The thiol additions to donor–acceptor cyclopropanes bearing electron-rich and electron-deficient aromatic
Ring Opening of Donor-Acceptor Cyclopropanes with the Azide Ion: A Tool for Construction of N-Heterocycles
作者:Konstantin L. Ivanov、Elena V. Villemson、Ekaterina M. Budynina、Olga A. Ivanova、Igor V. Trushkov、Mikhail Ya. Melnikov
DOI:10.1002/chem.201405551
日期:2015.3.23
general method for ringopening of various donor–acceptor cyclopropanes with the azide ion through an SN2‐like reaction has been developed. This highly regioselective and stereospecific process proceeds through nucleophilic attack on the more‐substituted C2 atom of a cyclopropane with complete inversion of configuration at this center. Results of DFT calculations support the SN2 mechanism and demonstrate
已经开发出一种通用的方法,可通过类似S N 2的反应,将叠氮离子与各种供体-受体环丙烷开环。这种高度区域选择性和立体选择性的过程是通过亲核攻击环丙烷的更取代的C2原子进行的,该中心的构型完全反转。DFT计算结果支持S N2机理,证明环丙烷的相对实验反应性与计算出的能垒之间具有良好的定性相关性。该反应为多种多官能叠氮化物提供了一种简单的方法,产率高达91%。这些叠氮化物具有很高的合成效用,并参与了面向多样性的合成,这是通过已开发的将其转变为五元,六元和七元N杂环以及复杂的环状化合物的多径策略证明的。包括天然产物和药物,如(-)-尼古丁和阿托伐他汀。
Formal Insertion of Thioketenes into Donor–Acceptor Cyclopropanes by Lewis Acid Catalysis
作者:André U. Augustin、Marius Busse、Peter G. Jones、Daniel B. Werz
DOI:10.1021/acs.orglett.7b03961
日期:2018.2.2
Donor–acceptorcyclopropanes were reacted under Lewis acid catalysis with 3-thioxocyclobutanones as surrogates for disubstituted thioketenes. A broad scope of 2-substituted tetrahydrothiophenes with a semicyclic double bond was obtained under mild conditions with high functional group tolerance and in excellent yield. A sequence of a formal [3 + 2]-cycloaddition followed by the subsequent release of