Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
J Org Chem. 2013 Feb 15;78(4):1508-18. doi: 10.1021/jo3025972. Epub 2013 Jan 29.
The synthesis and alkylation of chiral, nonracemic tropane- and homotropane-derived enamines is examined as an approach to enantioenriched α-alkylated aldehydes. The two bicyclic N auxiliaries, which differ by a single methylene group, give opposite senses of asymmetric induction on alkylation with EtI and provide modestly enantioenriched 2-ethylhexanal (following hydrolysis of the alkylated iminium). The observed stereoselectivity is supported by density functional studies of ethylation for both enamines.
作为一种获得手性α-烷基化醛的方法，我们研究了手性、非外消旋托品烷和同托品烷衍生的烯胺的合成和烷基化反应。这两个双环 N 助剂仅相差一个亚甲基，在手性诱导上烷基化时给出相反的结果，并且提供了中等程度的手性 2-乙基己醛（经烷基化亚胺水解后）。对于两种烯胺的乙基化的密度泛函研究支持了观察到的立体选择性。
