Synthesis of the neocarzinostatin chromophore A core diynene structure using an η<sup>2</sup>-hexacarbonyidicobalt mediated Aldol reaction
作者:Philip Magnus、Thomas Pitterna
DOI:10.1039/c39910000541
日期:——
The monoketal of cyclopentene-1,3-dione was converted into the η2-Co2(CO)6 neocarzinostatincore 19 in six steps; oxidative decomplexation in the presence of cyclohexa-1,4-diene gave the cycloaromatized adduct 22.
Allylic Oxidations Catalyzed by Dirhodium Catalysts under Aqueous Conditions
申请人:Doyle Michael P.
公开号:US20090093638A1
公开(公告)日:2009-04-09
The present invention relates to compositions and methods for achieving the efficient allylic oxidation of organic molecules, especially olefins and steroids, under aqueous conditions. The invention concerns the use of dirhodium (II,II) “paddlewheel complexes, and in particular, dirhodium carboximate and tert-butyl hydroperoxide as catalysts for the reaction. The use of aqueous conditions is particularly advantageous in the allylic oxidation of 7-keto steroids, which could not be effectively oxidized using anhydrous methods, and in extending allylic oxidation to enamides and enol ethers.
Dirhodium(II) Caprolactamate: An Exceptional Catalyst for Allylic Oxidation
作者:Arthur J. Catino、Raymond E. Forslund、Michael P. Doyle
DOI:10.1021/ja045330o
日期:2004.10.1
The oxidation of organic molecules represents a fundamentally important chemical process. Particularly important is allylicoxidation, whereby a single methylene unit is converted directly into a carbonyl group. In this communication, we report that dirhodium(II) caprolactamate [Rh2(cap)4] in combination with tert-butyl hydroperoxide (terminal oxidant) effectively catalyzes the allylicoxidation of
有机分子的氧化是一个非常重要的化学过程。特别重要的是烯丙基氧化,由此单个亚甲基单元直接转化为羰基。在这篇通讯中,我们报告了己内酰胺二铑 (II) [Rh2(cap)4] 与叔丁基过氧化氢(末端氧化剂)结合有效地催化了各种烯烃和烯酮的烯丙基氧化。该反应是完全选择性的,可以耐受空气/水分,并且可以在几分钟内使用低至 0.1 mol% 的催化剂进行。已经提出了涉及氧化还原链催化的机制建议,以及更高价的叔丁基过氧化二铑络合物的中介作用的证据。
Studies on the synthesis of the core structures of the antitumor agents neocarzinostatin, kedarcidin, C-1027 and maduropeptin
The bicyclo[7.3.0]dodecadiyne core structure of the antitumor agents neocarzinostatin, kedarcidin, C-1027 and maduropeptin can be readily constructed by an intramolecular aldol reaction to form the bond only if the C-6,7 triple bond is complexed as its η2Co2(CO)6-acetylene adduct.
Azido-Coronatine: A Useful Platform for “Click Chemistry”-Mediated Probe Synthesis for Bioorganic Studies
作者:Masahiro OKADA、Syuusuke EGOSHI、Minoru UEDA
DOI:10.1271/bbb.100518
日期:2010.10.23
azide-coronatine as a useful platform for azide alkyne cycloaddition ("click chemistry")-mediated synthesis of molecular probes. (+)-Azido-coronatine was synthesized in 10 steps with 11% yield using improved synthesis of coronafacic acid, in which the highly exo-selectiveDiels-Alderreaction (endo:exo > 1:25) is the key step. Azido coronatine was as effective as the original coronatine in a stomatal