A Convenient One-Pot Synthesis of 4-Substituted 3,5-Bis(alkoxycarbonyl) -4,5-dihydroisoxazole 2-Oxides from Aldehydes and Nitroacetic Esters in a Solid-Liquid Reaction System and Subsequent Deoxygenation
4-Substituted 3,5-bis(alkoxycarbonyl)-4,5-dihydroisoxazole 2-oxides are obtained from nitroacetic esters and imines which are prepared from aldehydes and isopropylamine in the presence of molecular sieves. Reduction of the N-oxides with trimethyl phosphite in dioxane gives the corresponding 4,5-dihydroisoxazoles in good yields.
diastereoselective and enantioselective formal [4+1] ylide annulation of chiral sulfonium salts with various substituted α-substituted nitroalkene leading to opticallyactive isoxazoline N-oxides using CF3SO3− as a key anion has been explored. The salient features of this methodology include high diastereo- and enantioselecties, easily available starting materials, mild reaction conditions, simple procedure
已经探索了使用CF 3 SO 3 -作为关键阴离子的手性锍盐与各种取代的α-取代硝基烯烃的非对映选择性和对映选择性形式[4+1]叶立德环化产生光学活性异恶唑啉N-氧化物。该方法的显着特点包括高非对映选择性和对映选择性、易于获得的起始材料、温和的反应条件、简单的程序、广泛的底物范围以及异恶唑啉N-氧化物可方便地转化为其他功能化化合物。
Catalytic Enantioselective Synthesis of 3,4,5-Trisubstituted Isoxazoline <i>N</i>
-Oxides and Regioselective Synthesis of 3,4,5-Trisubstituted Isoxazoles
作者:Subas Chandra Sahoo、Subhas Chandra Pan
DOI:10.1002/ejoc.201801693
日期:2019.2.14
A convenient catalytic asymmetric synthesis of 3,4,5‐trisubstituted isoxazoline N‐oxides and regioselective synthesis of 3,4,5‐trisubstitutedisoxazoles has been developed.
Highly diastereoselective condensation of α-nitro-esters with aldehydes catalyzed by zinc complexes of amino acids
作者:A. Chatterjee、S.C. Jha、N.N. Joshi
DOI:10.1016/s0040-4039(02)01047-x
日期:2002.7
Zinc complexes of amino acids efficiently catalyze the condensation between α-nitro-esters and a variety of aldehydes. An unusual domino reaction sequence leads to the diastereoselective formation of substituted isoxazoline N-oxides in high yields.