Synthesis of Optically Active<i>p</i>-Tolylsulfinylquinones
作者:M. Carmen Carreño、José L. García Ruano、Antonio Urbano
DOI:10.1055/s-1992-26189
日期:——
The title compounds 3a-e were prepared in only two steps from 1,4-dimethoxyaromatic precursors 1a-e by sulfinylation followed by oxidation with ammonium cerium(IV) nitrate.
General synthesis of chiral 2-p-tolylsulfinylquinones.
作者:M.Carmen Carreño、Jośe L. García Ruano、Jośe M. Mata、Antonio Urbano
DOI:10.1016/s0040-4020(01)87050-2
日期:1991.1
Optically pure (S)-p-tolylsulfinyl substituted quinones were synthesized by deketalization of the corresponding quinone bisketals obtained by Andersen's type synthesis starting from 2-bromo-1,4-dimethoxy aromatic derivatives, followed by anodic oxidation of the resulting sulfoxide.
Photoinduced Conformational Switch of Enantiopure Azobenzenes Controlled by a Sulfoxide
作者:M. Carmen Carreño、Isabel García、Irene Núñez、Estíbaliz Merino、María Ribagorda、Silvia Pieraccini、Gian Piero Spada
DOI:10.1021/ja070163o
日期:2007.6.6
Two series of enantiopure azobenzenes with a p-tolylsulfoxide at the ortho or meta position with respect to the azo group, have been regioselectively synthesized. Both can act as enantiopure molecular switches showing different structural features owing to the presence of the stereogenic sulfur. The photoisomerization process, studied by UV-vis, circular dichroism (CD), NMR, and chiral HPLC evidenced a double role of the sulfoxide. A transfer of chirality from the sulfoxide to the azo system was observed by CD in both cis and trans-isomers of the meta sulfinyl derivatives 3, whereas this perturbation was evident for the ortho sulfinyl series 7 only in the cis isomer. The NMR study evidenced that the s-cis rigid conformation of the bisaromatic sulfoxide was fixing a different orientation of the overall system in each series both in the trans and cis isomers, by forcing a final U-shaped structure in cis-3 and an S-shaped structure in cis-7. Very different values of specific optical rotations were measured in both trans and cis isomers, also reflecting the existence of distinct chiral entities in the photostationary states. The easy and reversible changes occurring between different conformational states could find applications in the photocontrol of several molecular switches.
Diastereoselective addition of 2-trimethylsilyloxyfuran to (S)-(+)-2-(p-tolylsulfinyl)-1,4-benzoquinone
作者:Margaret A Brimble、Letecia J Duncalf、David C.W Reid
DOI:10.1016/0957-4166(94)00383-m
日期:1995.1
The uncatalyzed addition of 2-trimethylsilyloxyfuran to (S)-(+)-2-(p-tolysulfinyl)-1,4-benzoquinone 1 afforded a3.4:1 ratio of the diastereomeric adducts 2:3. Acetonitrile was found to be the optimum solvent whilst the use of Lewis acid catalysts afforded lower overall yields.
CARRENO, M. CARMEN;RUANO, JOSE L. GARCIA;URBANO, ANTONIO, TETRAHEDRON LETT., 30,(1989) N0, C. 4003-4006
作者:CARRENO, M. CARMEN、RUANO, JOSE L. GARCIA、URBANO, ANTONIO