[2+2] Cycloaddition of ketenes with ynamides. A general method for the synthesis of 3-aminocyclobutenone derivatives
作者:Amanda L. Kohnen、Xiao Yin Mak、Tin Yiu Lam、Joshua R. Dunetz、Rick L. Danheiser
DOI:10.1016/j.tet.2005.11.088
日期:2006.4
Ynamides react with ketenes in [2+2] cycloadditions leading to a variety of substituted 3-aminocyclobut-2-en-1-ones. The ynamides employed in these reactions are readily available via the copper-promoted N-alkynylation of carbamates and sulfonamides with alkynyl bromides and iodides. The scope of the [2+2] cycloaddition with regard to both the ketene and ynamide component is described.
Synthesis of Polycyclic Benzofused Nitrogen Heterocycles via a Tandem Ynamide Benzannulation/Ring-Closing Metathesis Strategy. Application in a Formal Total Synthesis of (+)-FR900482
作者:Xiao Yin Mak、Aimee L. Crombie、Rick L. Danheiser
DOI:10.1021/jo2000308
日期:2011.3.18
variety of functionalized substituents at the position ortho to the nitrogen. In the second stage of the tandem strategy, ring-closingmetathesis generates the nitrogen heterocyclic ring. This two-step sequence provides efficient access to highly substituted dihydroquinolines, benzazepines, benzazocines, and related benzofused nitrogen heterocyclic systems. The application of this chemistry in a concise
Prins Cyclization in Ionic Liquid Hydrogen Fluoride Salts: Facile and Highly Efficient Synthesis of 4-Fluorinated Tetrahydropyrans, Thiacyclohexanes, and Piperidines
作者:Yuichiro Kishi、Shinsuke Inagi、Toshio Fuchigami
DOI:10.1002/ejoc.200800872
日期:——
Prinscyclization of homoallylic alcohols with various aldehydes was investigated in ionic liquid hydrogen fluoride (HF) salts, which played roles as a reaction medium, a catalyst, and a fluorine source. The reaction afforded the corresponding 4-fluorinated tetrahydropyrans in excellent yields with a high stereoselectivity (cis form exclusively). When benzaldehydes having a strongly electron-donating
The reaction of N-acyl-alpha-methoxyamines with allyl-, propargyl-, and benzylzinc bromides and Reformatsky reagents proceeds in THF at room temperature. Homoallyl- and homopropargylamines and beta-amino esters are synthesized in good yields.
SYNTHESIS OF YNAMIDES BY N-ALKYNYLATION OF AMINE DERIVATIVES. PREPARATION OF N-ALLYL-N-(METHOXYCARBONYL)-1,3-DECADIYNYLAMINE
作者:Kohnen, Amanda L.、Dunetz, Joshua R.、Danheiser, Rick L.、Denmark, Scott E.、Liu, Xiaorong