Asymmetric Synthesis of Antimicrotubule Biaryl Hybrids of Allocolchicine and Steganacin
作者:Agnès Joncour、Anne Décor、Jian-Miao Liu、Marie-Elise Tran Huu Dau、Olivier Baudoin
DOI:10.1002/chem.200601764
日期:2007.6.25
its stereochemical information to the biaryl axis. The coupling conditions were optimized, and two biphenylphosphane ligands (DavePhos and S-Phos) were found to give the highest yields and diastereoselectivities. A three-element stereochemical model was proposed to explain the observed diastereoselectivities. In a second key step, the medium ring of the target molecules was formed by a stereoselective
描述了包含七元或八元杂环介质环的新型轴向手性联芳基化合物5af的不对称合成。这些分子可以被认为是金属酚型和甜菊糖型天然产物的结构杂合体。该合成的特征是对映体-非对映选择性的联芳基铃木偶合,其中苄基立体中心有效地将其立体化学信息转移至联芳基轴。优化了偶联条件,发现两个联苯膦配体(DavePhos和S-Phos)具有最高的收率和非对映选择性。提出了三元素立体化学模型来解释观察到的非对映选择性。在第二个关键步骤中,计算表明,目标分子的中环是由立体选择性S(N)1型环脱水形成的,该环脱水可能涉及构型稳定的碳阳离子中间体。或者,在相同的Suzuki偶联产物上使用S(N)2型环化,以立体发散或立体会聚的方式得到靶分子。这些环化方法为目标杂合类似物5 af提供了ee值高于94%的目标。使用秋水仙碱(1)和N-乙酰基胆碱(3)作为参考,将所有类似物评估为抗微管剂,并针对一组癌细胞系进行评估。对于R,aR-