desilylative SE2′ reaction to the ambivalent 2-bromo-1-silyl-1,3-dienes provides a novel route to the highly enantioselective construction of tertiary and quaternary propargylic stereogenic centers via axially chiral allenylsilanes.
将Pd催化的S N 2'反应和脱甲硅烷基化的S E 2'反应逐步应用到矛盾的2-溴-1-甲硅烷基-1,3-二烯上,为叔和季炔丙基的高对映选择性构建提供了一条新途径通过轴向手性烯基硅烷形成立体中心。
The synthesis of αβ-unsaturated ketones from β-silylenones and β-silylynones
作者:Ian Fleming、David A. Perry
DOI:10.1016/s0040-4020(01)93277-6
日期:——
Conjugate addition, followed by alkylation, bromination and desilyl-bromination make the β-silylketone (4) an a3d3-synthon (5) and the β-silylynone (6) a 2a3d3-synthon (7).
共轭加成,然后进行烷基化,溴化和去甲硅烷基溴化反应,使β-甲硅烷基酮(4)成为3 d 3-合成子(5)和β-甲硅烷基酮(6)成为2a 3 d 3-合成子(7)。
Intermediates for the synthesis of 4-demethoxydaunorubicin
申请人:G. D. Searle & Co.
公开号:US04161480A1
公开(公告)日:1979-07-17
The present invention encompasses novel intermediates having the following structural formulas: ##STR1## wherein X is hydrogen, methoxy, or hydroxy; ##STR2## wherein X is hydrogen, methoxy, or hydroxy; and ##STR3## wherein X is hydrogen, methoxy, or hydroxy. Compounds of the present invention are useful in synthesizing 4-demethoxydaunorubicin, daunorubicin, adriamycin, and carminomycin which are potent antitumor agents.
The Diels–Alder route to allylsilanes from 1-trimethylsilylbutadienes
作者:Martin J. Carter、Ian Fleming、Alan Percival
DOI:10.1039/p19810002415
日期:——
which undergo clean protodesilylation with acid, and, with the acid and ester derived from the maleic anhydride adduct of (3), undergo epoxidation and sulphenylation reactions giving an allyl alcohol (33) and an allyl sulphide (37), respectively. The adducts from (20) can be hydrolysed to β-silylketones, which can be converted into enones by bromination. 1-Pentamethyldisilylbutadiene (15) is no more
Carbonium ion rearrangements controlled by the presence of a silyl group
作者:Ian Fleming、Shailesh K Patel
DOI:10.1016/s0040-4039(01)92922-3
日期:——
Tertiary alcohols with a λ-silyl group (3) generally undergo a simple carboniumionrearrangement in acid giving a single alkene product (4) with loss of the silyl group.