Mandal Tanmay, Samanta Sampak, Zhao Cong-Gui
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA.
Org Lett. 2007 Mar 1;9(5):943-5. doi: 10.1021/ol070209i. Epub 2007 Feb 7.
[reaction: see text] The first organocatalytic highly enantioselective nitroaldol reaction of alpha-ketophosphonates and nitromethane has been realized by using cupreine (2) or 9-O-benzylcupreine (3) as the catalyst. Both catalysts are highly reactive and highly enantioselective. alpha-Hydroxy-beta-nitrophosphonates have been synthesized in good yields and excellent enantioselectivities (>or=90% ee) at a low catalyst loading (5 mol %). These nitroaldol products may be reduced to the biologically significant beta-amino-alpha-hydroxyphosphonates with complete retention of the stereochemistry.
[反应：见正文] 使用铜试剂（2）或9-O-苄基铜试剂（3）作为催化剂，实现了首例α-酮膦酸酯与硝基甲烷的有机催化高对映选择性硝基羟醛反应。两种催化剂均具有高反应活性和高对映选择性。在低催化剂用量（5 mol%）下，已以良好的产率和优异的对映选择性（≥90% ee）合成了α-羟基-β-硝基膦酸酯。这些硝基羟醛产物可被还原为具有生物学意义的β-氨基-α-羟基膦酸酯，且立体化学完全保持不变。
