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
(4 + 3)-Cycloaddition of Donor–Acceptor Cyclopropanes with Thiochalcones: A Diastereoselective Access to Tetrahydrothiepines
作者:André U. Augustin、J. Luca Merz、Peter G. Jones、Grzegorz Mlostoń、Daniel B. Werz
DOI:10.1021/acs.orglett.9b03623
日期:2019.12.6
tetrahydrothiepines using donor-acceptorcyclopropanes. Thiochalcones, functioning as sulfur-containing four-atom building blocks, were reacted in a Lewisacidcatalyzed formal (4 + 3)-cycloaddition reaction with donor-acceptorcyclopropanes as three-atom building blocks. Under mild conditions various tetrahydrothiepines were synthesized in good yields in a stereospecific reaction with high functional group tolerance
Ketenedithioacetals as Surrogates for the Formal Insertion of Ketenes into Donor–Acceptor Cyclopropanes
作者:Alexander Lücht、Alexander Kreft、Peter G. Jones、Daniel B. Werz
DOI:10.1002/ejoc.202000233
日期:2020.5.10
Masked: Donor–acceptorcyclopropanes undergo a cycloaddition reaction with ketenedithioacetals under Lewis acid catalysis. Cleavage of the dithiane unit leads to cyclopentanones. As a result of this two‐step process, formally an acceptor‐substituted ketene is inserted into the three‐membered ring system.
Lewis Acid Catalyzed Ring-Opening 1,3-Aminothiolation of Donor–Acceptor Cyclopropanes Using Sulfenamides
作者:Avishek Guin、Thukaram Rathod、Rahul N. Gaykar、Tony Roy、Akkattu T. Biju
DOI:10.1021/acs.orglett.0c00483
日期:2020.3.20
donor-acceptor (D-A) cyclopropanes using sulfenamides has been demonstrated. The insertion of the C-C σ-bond of D-A cyclopropanes into the S-N σ-bond of sulfenamides allows the synthesis of diverse γ-aminated α-thiolated malonic diesters in moderate to good yields (up to 87%) with good functional group compatibility. The stereospecificity of the reaction was demonstrated using enantiomericallypure D-A cyclopropane
Design, Preparation, X-ray Crystal Structure, and Reactivity of <i>o</i>-Alkoxyphenyliodonium Bis(methoxycarbonyl)methanide, a Highly Soluble Carbene Precursor
作者:Chenjie Zhu、Akira Yoshimura、Lei Ji、Yunyang Wei、Victor N. Nemykin、Viktor V. Zhdankin
DOI:10.1021/ol301268j
日期:2012.6.15
The preparation, X-ray structure, and reactivity of new, highly soluble, and reactive iodonium ylides derived from malonate methyl ester and bearing an ortho substituent on the phenyl ring are reported. These new reagents show higher reactivity than common phenyliodonium ylides in the Rh-catalyzed cyclopropanation, C–H insertion, and transylidation reactions under homogeneous conditions.