Potassium carbonate–silica: a highly effective stationary phase for the chromatographic removal of organotin impurities
作者:David C. Harrowven、Dennis P. Curran、Sarah L. Kostiuk、Ian L. Wallis-Guy、Sally Whiting、Kerri J. Stenning、Bencan Tang、Emma Packard、Lana Nanson
DOI:10.1039/c0cc01328e
日期:——
Organotin impurities in product mixtures can be reduced from stoichiometric levels to â¼15 parts per million by column chromatography using 10% w/w anhydrous potassium carbonateâsilica as a stationary phase.
A new diastereoselective approach to simplified Dynemicin analogues
作者:Giuseppe Guanti、Renata Riva
DOI:10.1039/b002031l
日期:——
The stereoselective synthesis of new simplified Dynemicin
analogues is reported: key steps of the sequence are the regio- and
diastereo-selective functionalization of a quinoline nucleus, bearing a
substituent with a stereogenic centre, and the formation of the 10-membered
cyclic enediyne system by Pd-catalyzed Stille-like reaction.
Enzymatically Asymmetrised Chiral Building Blocks for the Synthesis of Complex Natural Product Analogues: The Synthesis of Dynemicin Analogues from 2-(Quinolin-4-yl)propane-1,3-diol
Full details of our synthetic approaches directed towards the enantioselective synthesis of new dynemicinanalogues each containing a side-arm (a “handle”) incorporating a protected alcohol are reported.
A synthetic approach to the 9-membered enediyne analogue 3 of neocarzinostatin chromophore by using a palladium-catalyzed cross coupling reaction and the conformational analyses of diynes 11 and 12 based on MM2 calculation are described.
作者:Donald E. Herr、Michael D. Mays、Richard D. McCullough、Allan B. Bailey、Dwaine O. Cowan
DOI:10.1021/jo960120i
日期:1996.1.1
A systematic synthetic study of the pi-donor tetratellurafulvalene (TTeF, 6) has resulted in an optimized preparation producing repeatable yields of over 20%. The use of a "one-step" Li/Sn metal exchange/Te(0) insertion procedure and freshly prepared microcrystalline Te(0) serve to drive toward products, the equilibria converting (Z)-1,2-bis(trimethylstannyl)ethylene (1) to its corresponding metal-exchanged
对pi供体四氟富勒瓦烯(TTeF,6)的系统合成研究已导致制备优化的制剂,可重复产率超过20%。使用“一步式” Li / Sn金属交换/ Te(0)插入程序和新鲜制备的微晶Te(0)有助于驱使产品平衡转化(Z)-1,2-双(三甲基锡烷基)乙烯(1)生成相应的金属交换乙烯基锂物质,然后生成二硬脂酸锂5。此外,在这些金属交换反应中使用LiCl作为添加剂来增强n-BuLi的反应性还可以提高收率和重现性。在最后的环化步骤中缓慢加入1当量的四卤乙烯有利于产生TTeF的分子内反应与导致寡聚副产物的分子间反应。