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Studies on Remote Asymmetric Induction in Cycloaddition Reactions using Novel Chiral Sulfoxides

新型手性亚砜环加成反应中远程不对称诱导的研究

基本信息

批准号：
08672434
负责人：
ARAI Yoshitsugu
金额：
$ 1.15万
依托单位：
GIFU PHARMACEUTICAL UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

Three types of chiral sulfoxides having a 5-membered aromatic heterocycle (furan, thiophene and pyrrole) were synthesized and high levels of diastereoselectivity in addition reactions were observed.1.Stereoselective reductionReduction of chiral 3-(p-tolylsulfinyl)-2-thienyl alkyl (and aryl) keones with diisobutylaluminum hydride afforded the corresponding (S)-thienylcarbinols as the major product, while the similar reduction in the presence of a Lewis acid or lithium tri-sec-butylborohydride (L-Selectride^<<encircledR>>) reduction afforded (R)-alcohols as the major isomer.2.Stereoselective hetero Diels-Alder reactionA lanthanide triflate-promoted hetero Diels-Alder reaction of chiral 3-(p-tolylsulfinyl) furaldehyde with Danishefsky's diene proceeded to give the adduct with excellent distereoselectivity.3.Stereoselective Diels-Alder reaction2-Futyl and 2-thienyl alpha, beta-enones, bearing a chiral p-tolylsulfinyl group in the heterocycle, served as an efficient dienophile in the Diels-Alder reaction, where the catalytic use of aluminium chloride or a lanthanide triflate effected these cycloadditions with cyclopentadiene affording the endo adduct with high diastereoselectivity, ranging from 91% to 98%. Similarly the enone to which a chiral p-tolylsulfinyl pyrrole moiety was incorporated also underwent the cycloaddition with up to 89% diastereoisomeric excess in the presence of 1 eqiuv. of the Lewis acid. In particular for the Diels-Alder reaction, the auxiliary (i.e.the sulfinyl pyrrole) was recovered after use without any loss of optical purity.

合成了三种具有五元芳香族杂环的手性亚砜(呋喃、噻吩和吡咯)，并观察到在加成反应中高水平的非对映选择性。1.手性3-(对甲苯亚磺基)-2-噻吩基(和芳基)酮与二异丁基氢化铝还原得到相应的(S)-噻吩醇为主要产物，而在Lewis酸或三叔丁基硼氢化锂(L)存在下的类似还原反应。2.立体选择性的杂Diels-Alder反应3-(对甲苯基亚磺基)呋喃甲醛与Danishefsky‘s二烯的催化作用下，手性3-(对甲苯基亚磺基)呋喃醛与丹尼舍夫斯基的二烯发生异Diels-Alder反应，得到具有良好的立体选择性的加合物。3.立体选择性的Diels-Alder反应，杂环中含有手性对甲苯基亚磺基的2-富丁基和2-噻吩基的α，β-烯酮类化合物，在Diels-Alder反应中是一个有效的亲二烯化合物，其中三氟化铝或稀土的催化作用使这些环加成反应与环戊二烯发生反应，得到具有高非对映选择性的环加成产物，其选择性范围从91%到98%。类似地，含有手性对甲苯基亚硫基吡咯部分的烯酮也进行了环加成反应，在1eQiuv存在下，非对映异构体过剩达89%。刘易斯酸。特别是对于Diels-Alder反应，使用后回收了助剂(即亚磺基吡咯)，而不损失任何光学纯度。