Chromium(II)-Mediated Stereodivergent Additions of Allylic Phosphates and Halides to Aldehydes
摘要:
The addition of gamma-disubstituted allylchromium(III) reagents to aldehydes proceeds in a stereodivergent manner, in contrast to the case of gamma-monosubstituted allylchromium(III) species. The method allows the preparation of a variety of homoallylic alcohols bearing a quaternary center of defined relative configuration in the alpha-position. The preparation of both stereomeric homoallylic alcohols 13 is possible by using either of the two (E)- or (Z)-allylic precursors. The reaction has been extended to a gamma-monosubstituted beta-(trimethylsilyl)allylic system. The intermediate allylic chromium(III) reagents can be conveniently prepared from the corresponding phosphates (or chlorides) in DMPU or THF in the presence of catalytic amounts of LiI.
A regiodefined synthesis of α-trimethylsilyl ketones catalyzed by rhodium(I) hydride complex
作者:Susumu Sato、Isamu Matsuda、Yusuke Izumi
DOI:10.1016/0022-328x(88)80214-6
日期:1988.4
Regiodefined synthesis of α-trimethylsilyl ketones is attained by one of three different routes: isomerization of β-trimethylsilyl allyl alcohols (route A), isomerization of β′-trimethylsilyl allyl alcohols (route B), and dehydrogenation of β-trimethylsilyl alcohols via transfer hydrogenation to α,β-enones (route C). All of these procedures are catalyzed efficiently by HRh(PPh3)4 at about 100 °C. Route
SATO, FUMIE;TANAKA, YOUICHI;KANBARA, HIROSHI, J. CHEM. SOC. CHEM. COMMUN., 1983, N 18, 1024-1025
作者:SATO, FUMIE、TANAKA, YOUICHI、KANBARA, HIROSHI
DOI:——
日期:——
SATO, SUSUMU;MATSUDA, ISAMU;IZUMI, YUSUKE, J. ORGANOMET. CHEM., 344,(1988) N 1, 71-88
作者:SATO, SUSUMU、MATSUDA, ISAMU、IZUMI, YUSUKE
DOI:——
日期:——
Chromium(II)-Mediated Stereodivergent Additions of Allylic Phosphates and Halides to Aldehydes
作者:Stefan Nowotny、Charles E. Tucker、Carole Jubert、Paul Knochel
DOI:10.1021/jo00114a026
日期:1995.5
The addition of gamma-disubstituted allylchromium(III) reagents to aldehydes proceeds in a stereodivergent manner, in contrast to the case of gamma-monosubstituted allylchromium(III) species. The method allows the preparation of a variety of homoallylic alcohols bearing a quaternary center of defined relative configuration in the alpha-position. The preparation of both stereomeric homoallylic alcohols 13 is possible by using either of the two (E)- or (Z)-allylic precursors. The reaction has been extended to a gamma-monosubstituted beta-(trimethylsilyl)allylic system. The intermediate allylic chromium(III) reagents can be conveniently prepared from the corresponding phosphates (or chlorides) in DMPU or THF in the presence of catalytic amounts of LiI.
SATO, FUMIE;TANAKA, YOUICHI;SATO, MASAO, J. CHEM. SOC. CHEM. COMMUN., 1983, N 4, 165-166