3,5-Dioxopimelates as new synthetic building blocks. Cyclocondensation with 1,2-, 1,3- and 1,4-dinucleophiles
摘要:
Cyclocondensation reactions of 3,5-dioxopimelates, new and versatile synthetic building blocks, with hydrazines, urea, thiourea and phenylene-1,2-diamines allow for a convenient synthesis of various heterocycles containing two ester-substituted side-chains. (C) 2012 Elsevier Ltd. All rights reserved.
First synthesis of functionalized 5-aryl-3-(trifluoromethyl)phenols by regioselective [3+3] cyclocondensations of 1,3-bis(silyloxy)-1,3-butadienes with 3-aryl-3-silyloxy-1-trifluoromethyl-2-en-1-ones
A variety of functionalized 5-aryl-3-(trifluoromethyl)phenols were prepared by the first TiCl4-mediated [3+3] cyclocondensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-aryl-3-trimethylsilyloxy-1-trifluoromethyl-2-en-1-ones.
Synthesis of Functionalized Diaryldiazenes by Formal [3+3] Cyclizations of 1,3-Bis(silyloxy)-1,3-butadienes with 2-Aryldiazenyl-3-silyloxy-2-en-1- ones
The formal [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 2-aryldiazenyl-3-silyloxy- 2-en-1-ones afforded a variety of functionalized diaryl-diazenes.
were prepared by formal [3 + 3] cyclization of 1,3-bis(silylenolethers) with 3-silyloxy-2-en-1-ones or 1,1-diacetylcyclopropane to give functionalized salicylates, Suzuki cross-coupling reactions of the corresponding triflates, and subsequent BBr3-mediated lactonization. A second approach to dibenzo[b,d]pyran-6-ones relies on the [3 + 3] cyclization of 1,3-bis(silylenolethers) with 1-(2-methoxyphe
Neighboring group participation in Lewis acid-promoted [3 + 4] and [3 + 5] annulations. The synthesis of oxabicyclo[3.n.1]alkan-3-ones
作者:Gary A. Molander、Kimberly O. Cameron
DOI:10.1021/ja00056a002
日期:1993.2
2-(alkoxycarbon)-m-oxabicyclo[3.n.1]alkan-3-ones can be constructed by this process in which two new carbon-carbon bonds are generated. Unusually high regioncontrol is observed, and good to excellent stereochemicalcontrol can be achieved at virtually every position on the new carbocycles. Intramolecular neighboringgroupparticipation is proposed to explain the unusually high selectivities attained in the annulation
Regioselective synthesis of 3-(methylthio)phenols by formal [3+3]-cyclocondensations of 3-oxo-bis(methylthio)ketenacetals with 1,3-bis(trimethylsilyloxy)-1,3-butadienes and 1,3-dicarbonyl dianions
The cyclization of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-oxo-bis(methylthio)ketenacetals afforded 3-(methylthio)phenols containing an acyl or ester substituent located at position 2. The cyclization of free 1,3-dicarbonyl dianions with 3-oxo-bis(methylthio)ketenacetals resulted in the formation of regioisomeric products containing an acyl group located at position 6.