Callebaut Gert, Colpaert Filip, Nonn Melinda, Kiss Loránd, Sillanpää Reijo, Törnroos Karl W, Fülöp Ferenc, De Kimpe Norbert, Mangelinckx Sven
Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Org Biomol Chem. 2014 Jun 7;12(21):3393-405. doi: 10.1039/c4ob00243a. Epub 2014 Apr 17.
Mannich-type reactions of O-Boc glycolic esters across chiral N-sulfinyl-α-chloroaldimines resulted in the efficient and syn-stereoselective synthesis of new γ-chloro-α-hydroxy-β-amino esters (dr > 99 : 1). The α-coordinating ability of the chlorine atom was of great importance for the diastereoselectivity of the Mannich-type reaction and overruled the chelation of the sulfinyl oxygen with the lithium ion of the incoming E-enolate in the transition state model. These novel chloroisothreonine derivatives proved to be excellent building blocks in asymmetric synthesis of novel syn-β,γ-aziridino-α-hydroxy esters and biologically relevant trans-oxazolidinone carboxylic esters.
O-叔丁氧羰基乙醇酸酯与手性N-亚磺酰基-α-氯代醛亚胺的曼尼希型反应高效且立体选择性地合成了新的γ-氯-α-羟基-β-氨基酯（非对映体比例>99:1）。氯原子的α配位能力对曼尼希型反应的非对映选择性至关重要，并且在过渡态模型中推翻了亚磺酰基氧与 incoming E-烯醇锂的锂离子的螯合作用。这些新型氯代异苏氨酸衍生物被证明是新型顺式-β,γ-氮丙啶基-α-羟基酯和具有生物学相关性的反式恶唑烷酮羧酸酯不对称合成中的优秀砌块。
