Unsaturated β-ketoesters as versatile electrophiles in organocatalysis
作者:Susy Piovesana、Daniele M. Scarpino Schietroma、Ludovico G. Tulli、Mattia R. Monaco、Marco Bella
DOI:10.1039/c003296d
日期:——
Beta-ketoesters, which have widely been employed as nucleophiles, are also useful electrophiles in organocatalytic quinine mediated cascade reactions, leading to the formation of products bearing multiple stereocenters in high stereoselectivity.
diastereoselective Henry reaction of various aldehydes with nitroethane was developed using the guanidine-thioureabifunctional catalyst 1 (syn selectivity of 86:14 to 99:1 with 84–99 % ee). A variety of nitroalkanes was treated with unbranched and branched aldehydes and gave nitro alcohols with high syn diastereoselectivities (90:10 to 99:1) and high enantioselectivities (85–95 % ee). This reaction was successfully
作者:Maurice A. Marsini、Yaodong Huang、Ryan W. Van De Water、Thomas R. R. Pettus
DOI:10.1021/ol0710257
日期:2007.8.1
Syntheses of several unique spironitronates are reported. The key transformation involves the first known example of an ipso oxidative cyclization of nitro functionality. Oxidation proceeds from both o- and p-phenols. Reductions of these compounds provide novel spiroisoxazoline derivatives.