Organocatalytic Asymmetric Mannich Addition of 3-Fluorooxindoles to Dibenzo[<i>b</i>,<i>f</i>][1,4]oxazepines: Highly Enantioselective Construction of Tetrasubstituted C–F Stereocenters
作者:Bing-Yu Li、Ye Lin、Da-Ming Du
DOI:10.1021/acs.joc.9b01507
日期:2019.9.20
application in medicinal chemistry. An organocatalyzed asymmetricMannichreaction of 3-fluorooxindoles with dibenzo[b,f][1,4]oxazepines affording various seven-member cyclic amines containing chiral tetrasubstituted C–F stereocenters was developed. These reactions which were catalyzed by a bifunctional Cinchona alkaloid-derived thioureacatalyst afforded a wide range of substrates in moderate to high
catalytic asymmetric synthesis of new dibenzo[b,f][1,4]-oxazepine-fused 1,2-dihydropyridines (DHPs) has been described under metal-free conditions. This reaction proceeds through proline-catalyzed direct Mannich/cyclization between seven-membered dibenzo[b,f][1,4]-oxazepine-imines and aqueous glutaraldehyde, followed by IBX-mediated site-selective dehydrogenative oxidation in one-pot operation with high
An efficient visible-light-induced Staudinger [2 + 2] annulation reaction between α-diazo ketones and dibenzo[b,f][1,4]oxazepine/thiazepine-imines under catalyst-free conditions has been developed. This protocol provides a facile method to synthesize tetracyclic dibenzo[b,f][1,4]oxazepine/thiazepine-fused β-lactams bearing a quaternary carbon center with a broad substrate scope and high efficiency
开发了一种在无催化剂条件下,α-重氮酮与二苯并[ b , f ][1,4]氧氮杂/硫氮杂亚胺之间有效可见光诱导的施陶丁格[2+2]成环反应。该方案提供了一种简便的方法来合成具有季碳中心的四环二苯并[ b,f ][1,4]氧氮杂/硫氮杂稠合β-内酰胺,具有广泛的底物范围和高效率(37个例子,高达>99%屈服)。