Diastereoselective Nucleophilic Addition to Aldehydes with Polar α- and α,β-Substituents
作者:Tessie Borg、Jakob Danielsson、Maziar Mohiti、Per Restorp、Peter Somfai
DOI:10.1002/adsc.201100173
日期:2011.8
The stereoselectivities obtained in Lewis acid-promoted Mukaiyama aldol additions and Sakurai allylations of mono-, and syn- and anti-disubstituted aldehydes possessing various polar α- and β-substituents under non-chelating conditions are presented. The stereochemical outcome in the nucleophilic addition to α-substituted aldehydes containing an α-benzyloxy, α-fluoro or α-sulfonamide substituent are accurately
在路易斯酸促进的Mukaiyama羟醛加成物和Sakurai烯丙基化的单,反和反式和反式中获得的立体选择性提出了在非螯合条件下具有各种极性α-和β-取代基的β-二取代醛。通过目前的立体诱导模型可以准确地预测亲核加成到含有α-苄氧基,α-氟或α-磺酰胺取代基的α-取代醛中的立体化学结果。相反,不能通过相同的模型来合理化通过将空间上需要的亲核试剂加到α-氯取代的醛中而获得的选择物,并讨论了另一种选择。除α,β-二取代醛外,立体化学结果更为复杂,无法使用当前模型进行预测。