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.
Regioselective [3+3] Cyclization of 1,3-Bis(silyloxy)buta-1,3-dienes with 1,1,1-Trifluoro-4-(silyloxy)alk-3-en-2-ones: New and Convenient Synthesis of Functionalized 5-Alkyl-3-(trifluoromethyl)phenols
作者:Stefan Büttner、Alina Bunescu、Sebastian Reimann、T. H. Tam Dang、Thomas Pundt、Renske Klassen、Andreas Schmidt、Nazken K. Kelzhanova、Zharylkasyn A. Abilov、Tariel V. Ghochikyan、Ashot S. Saghiyan、Alexander Villinger、Helmut Reinke、Anke Spannenberg、Peter Langer
DOI:10.1002/hlca.201200056
日期:2013.1
Functionalized 5‐alkyl‐3‐(trifluoromethyl)phenols were prepared by formal [3+3] cyclization of 1,3‐bis(silyloxy)buta‐1,3‐dienes with 1,1,1‐trifluoro‐4‐(silyloxy)alk‐3‐en‐2‐ones derived from 1,1,1‐trifluoroalkane‐2,4‐diones. The latter were prepared by condensation of the dianion of 1,1,1‐trifluoropentane‐2,4‐dione with alkyl halides.
Chelation-control in the formal [3+3] cyclization of 1,3-bis-(silyloxy)-1,3-butadienes with 1-hydroxy-5-silyloxy-hex-4-en-3-ones. One-pot synthesis of 3-aryl-3,4-dihydroisocoumarins
The [3+3] cyclization of 1,3-bis(silyloxy)-1,3-butadienes with 1-hydroxy-5-silyloxy-hex-4-en-3-ones resulted in the one-pot formation of 3-aryl-3,4-dihydroisocoumarins. The reactions proceeded by regioselective cyclization to give 6-(2-aryl-2-chloroethyl)salicylates, which underwent a silica gel-mediated lactonization. The cyclizations of protected 1-amino-5-silyloxy-hex-4-en-3-ones proved to be not
3-Methoxalylchromones – versatile reagents for the regioselective synthesis of functionalized 2,4′-dihydroxybenzophenones, potential UV-filters
作者:Viktor O. Iaroshenko、Alina Bunescu、Anke Spannenberg、Linda Supe、Maria Milyutina、Peter Langer
DOI:10.1039/c1ob05931a
日期:——
The reaction of 1,3-bis-silyl enol ethers with 3-methoxalylchromones affords a great variety of functionalised 2,4â²-dihydroxybenzophenones. These products are formed by a domino Michael/retro-Michael/Mukaiyama-aldol reaction. The synthesized compounds are promising candidates for the synthesis of the novel UV-A/B and UV-B filters.
Reaction of 1,3‐Bis(trimethylsilyloxy)‐1,3‐butadienes with 2,4,6‐Tris(trifluoromethyl)‐1,3,5‐triazine: Planning and Serendipity
作者:Viktor O. Iaroshenko、Alina Bunescu、Anke Spannenberg、Peter Langer
DOI:10.1002/chem.201100379
日期:2011.6.20
Tri and you will succeed! A new type of formal [3+3] cyclization reaction of 2,4,6‐tris(trifluoromethyl)‐1,3,5‐triazine with 1,3‐bis(trimethylsilyloxy)‐1,3‐butadienes has been discovered that provides a convenient approach to functionalized 2,6‐bis(trifluoromethyl)‐1,4‐dihydro‐4‐oxopyridones (see scheme). The mechanism was studied by the isolation of an unusual tricyclic intermediate.