Asymmetric syntheses via heterocyclic intermediates-XXII
作者:Ulrich Schöllkopf、Joachim Nozulak、Ulrich Groth
DOI:10.1016/s0040-4020(01)82426-1
日期:1984.1
Enantioselective syntheses of α-alkenyl glycines of type 10 and of type 23 are described that provide these uncommon amino acids with predictable configuration and with ee-values of >95%. Both approaches are based on the bislactim ether method developed by Schöllkopf . As for 10: The lithiated bis-lactim ether 6 of cyclo (L-val-gly) is reacted with 2-[(dimethyl t-butyl)silyl]alkanals 2 to give the
Free radical addition to branched allylsilanes: stereoselective formation and elimination of β bromosilanes
作者:Ned A. Porter、Guiru Zhang、Aimee D. Reed
DOI:10.1016/s0040-4039(00)00902-3
日期:2000.7
Lewis acid-promoted free radicaladdition to 3-silyl-1-butenes occurs in good yield to give predominantly the cis-substituted alkene. The transfer reaction occurs by atom-transfer addition of the alkyl bromide precursor, an addition that occurs by Felkin–Anh control. Stereoselective anti elimination of the intermediate β-silylhalide gives the cis olefin.
Highly Torquoselective Electrocyclizations and Competing 1,7-Hydrogen Shifts of 1-Azatrienes with Silyl Substitution at the Allylic Carbon
作者:Zhi-Xiong Ma、Ashay Patel、K. N. Houk、Richard P. Hsung
DOI:10.1021/acs.orglett.5b00727
日期:2015.5.1
Highly torquoselective electrocyclizations of chiral 1-azatienes are described. These 1-azatrienes,Contain an allylic stereocenter that is substituted with a silyl group and are derived in situ from condensation of gamma-silyl-substituted enals with vinylogous amides. The ensuing stereoselective ring closure are part of a tandem sequence that constitutes an aza-[3 + 3] aimulation method for constructing 1,2-dihydropyridines. several mechanisms:for the formal 1,7-hydrogen 'shift of these 1-azattienes vtiere evaluated computationally.
[EN] SILYLATED AZULENYL NITRONE SPIN TRAPS AS CHROMOTROPIC SUPEROXIDE DETECTORS<br/>[FR] PIÈGES DE SPIN D'AZULÉNYL NITRONE SILYLÉE COMME DÉTECTEURS DE SUPEROXYDE CHROMOTROPES
申请人:FLORIDA INT UNIV BOARD TRUSTEES
公开号:WO2013067084A1
公开(公告)日:2013-05-10
Silylated nitrones and methods of detecting and/or superoxide using silylated nitrones are disclosed herein.
本文揭示了硅烷基化的亚硝酮及利用硅烷基化的亚硝酮检测和/或超氧化物的方法。
Efficient Synthesis of Branched Propargyl- and Allylsilanes
作者:Lutz F. Tietze、Thomas Neumann、Masahiro Kajino、Martina Pretor
DOI:10.1055/s-1995-4034
日期:1995.8
The transformation of α-silylated aldehydes 3a-h into the propargylsilanes 5a-k and the (Z)-allylsilane 6 is described. The readily available tert-butylimine 1 of acetaldehyde is silylated and alkylated in a one-pot procedure to obtain the α-silylated aldehydes 3a-h after hydrolysis of the imine moiety in 77-96% yield. C-1 homologation by the Corey-Fuchs method gave 1,1-dibromoallylsilanes 4a-h in 70-96% yields which can be transformed into the mono- and disubstituted propargylsilanes 5a-k in 33-95% yield. Hydrogenation of the propargylsilanes e.g. 5e with Ni(OAc)2/NaBH4 gives the (Z)-allylsilane 6a in 80% yield.