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1.
Langer P Armbrust H Eckardt T Magull J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2002,8(6):1443-1455
The Lewis acid mediated cyclization of epoxides with 1,3-bis(trimethylsilyloxy)-1,3-butadienes, electroneutral equivalents of 1,3-dicarbonyl dianions, results in the formation of 2-alkylidenetetrahydrofurans with a great variety of substitution patterns and functional groups. This includes the synthesis of 2,3'-bifuranylidenes and 7-oxabicyclo[4.3.0]nonanes. The cyclization of dienes with functionalized epoxides containing base-labile groups proceeds with good chemoselectivity. In all reactions, good regio- and E diastereoselectivities are observed. Based on the stereoselectivities observed for reactions of 1,2-disubstituted epoxides, a working hypothesis for the mechanism of the reaction is suggested. 相似文献
2.
Treatment of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with alpha-chlorocarboxylic acid chlorides resulted in chemo- and regioselective formation of 6-chloro3,5-dioxo esters, which were regioselectively converted into functionalised 3(2H)furanones. Chemo- and regioselective condensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with alpha-chloroacetic dimethyl acetal afforded 6-chloro-5-methoxy-3-oxo esters, which could be regio- and stereoselectively transformed into 2-alkylidene-4-methoxytetrahydrofurans. 相似文献
3.
Stefanie Reim Ibrar Hussain Zafar Ahmed Alexander Villinger 《Tetrahedron letters》2008,49(33):4901-4904
The reaction of 2-chloro-1,3-bis(trimethylsilyloxy)-1,3-butadienes with various electrophiles allows a convenient synthesis of chlorinated molecules which are not readily available by other methods. 相似文献
4.
Synthesis of functionalized diaryl sulfides based on regioselective one-pot cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes 总被引:1,自引:0,他引:1
Functionalized diaryl sulfides were prepared based on one-pot cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes. 相似文献
5.
The first fluoroalkylated 1,3-bis(silyloxy)-1,3-butadienes have been prepared. Their reaction with oxalyl chloride provides a convenient approach to fluoroalkylated γ-alkylidenebutenolides. 相似文献
6.
A new strategy for the synthesis of medium-sized bicyclic gamma-alkylidenebutenolides is reported which involves Me(3)SiOTf-catalyzed cyclization of cyclic 1, 3-bis(trimethylsilyloxy)-1,3-butadienes with oxalyl chloride. 相似文献
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Functionalized and sterically encumbered diaryl sulfides were prepared based on [3+3] cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-dienes. 相似文献
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Muhammad A. Rashid Bettina Appel Vahuni Karapetyan Helmut Reinke Peter Langer 《Tetrahedron》2008,64(22):5416-5425
Functionalized 1-azaxanthones (5-oxo-5H-[1]-benzopyrano[2,3-b]pyridines) were prepared by TMSOTf-mediated condensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-cyanochromones and subsequent base-mediated domino ‘retro-Michael/nitrile-addition/heterocyclization’ reaction. 相似文献
12.
Regioselective synthesis of sterically encumbered diaryl ethers based on one-pot cyclizations of 4-aryloxy-1,3-bis(trimethylsilyloxy)-1,3-dienes 总被引:1,自引:0,他引:1
Sterically encumbered diaryl ethers are prepared based on formal [3+3] cyclizations of novel 4-aryloxy-1,3-bis(trimethylsilyloxy)-1,3-dienes. 相似文献
13.
Functionalized amino- and nitro-substituted biaryls and dibenzo[b,d]pyrid-6-ones (6(5H)-phenanthridinones) were prepared by [3+3]cyclocondensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with nitro-substituted 1-aryl-1-silyloxy-1-en-3-ones and subsequent hydrogenation. 4-Nitro- and 4-aminophenols were prepared based on formal [3+3] cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-ethoxy-2-nitro-2-en-1-ones. 相似文献
14.
The cyclocondensation of 4-chloro-2-oxo-2H-chromene-3-carbaldehyde with 1,3-bis(silyloxy)-1,3-butadienes provides a convenient synthesis of benzo[c]chromen-6-ones. 相似文献
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2-(Phenylthio)benzoates containing a remote halide function are regioselectively prepared by ‘[3+3] cyclization/homo-Michael’ reactions of 1-methoxy-1-trimethylsilyloxy-3-phenylthio-1,3-butadienes with 1,1-diacylcyclopropanes. 相似文献
17.
Christian Haase 《Tetrahedron》2009,65(23):4530-3950
The acid-mediated reaction of amines with γ-alkylidenebutenolides, readily available by cyclization of 1,3-bis(silyloxy)-1,3-butadienes with oxalyl chloride, allows a convenient synthesis of a variety of 5-alkylidene-2,5-dihydropyrrol-2-ones. The configuration of the exocyclic double bond of the products depends on the substitution pattern of the products. 相似文献
18.
Functionalized arenes were prepared by chelation-controlled ‘[3+3] cyclization/homo-Michael’ reactions of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with benzyloxy- or methoxy-substituted 1,1-diacylcyclopropanes. 相似文献
19.
Functionalized 4-nitro- and 4-aminophenols were regioselectively prepared based on [3+3] cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-ethoxy-2-nitro-2-en-1-ones. 相似文献
20.
4-Alkyl- and 4-aryl-6-(perfluoroalkyl)salicylic acid derivatives were regioselectively prepared by [3+3] cyclization of 1,3-bis(silyl enol ethers) with 3-silyloxy-1-(perfluoroalkyl)prop-2-en-1-ones. 相似文献