Highly enantioselective direct Mannich reaction of seven-membered cyclic imines dibenzo[b,f][1,4]oxazepines with acetone via organocatalysis
作者:You-Qing Wang、Yuan-Yuan Ren
DOI:10.1016/s1872-2067(14)60225-4
日期:2015.1
dibenzo[ b,f ][ 1,4 ]oxazepines as seven-membered cyclic imines underwent a highly enantioselective direct Mannichreaction with acetone when catalyzed by proline. These reactions gave a range of optically active β-carbonyl seven-membered N -heterocycles with excellent enantioselectivity (93%–98% ee). With 2-butanone as a Mannich donor, the single regioselective product was obtained with 96%–97% ee. The absolute
摘要 各种取代的二苯并[ b, f ][ 1,4 ]氧氮杂作为七元环亚胺,在脯氨酸催化下与丙酮发生高度对映选择性的直接曼尼希反应。这些反应产生了一系列具有优异对映选择性 (93%–98% ee) 的光学活性 β-羰基七元 N-杂环。以 2-丁酮作为曼尼希供体,获得了具有 96%–97% ee 的单一区域选择性产物。通过对其衍生物的 X 射线单晶分析,产物的绝对构型被指定为 R。
Enantioselective addition of Et2Zn to seven‐membered cyclic imines catalyzed by a (R)-VAPOL-Zn(II) complex
作者:Lode De Munck、Verena Sukowski、Carlos Vila、José R. Pedro
DOI:10.1016/j.tetlet.2017.07.042
日期:2017.8
substituted dibenzo[b,f][1,4]oxazepines underwent an enantioselective alkylation with Et2Zn catalyzed by a (R)-VAPOL-Zn(II) complex. The corresponding chiral 11-ethyl-10,11-dihydrodibenzo[b,f][1,4]oxazepine derivatives were obtained with good yields and moderate enantioselectivities. This represents the first example of enantioselectiveaddition of Et2Zn to cyclic aldimines.
aerobic oxidative synthesis of 2-arylbenzo[d]oxazoles, 2-substituted benzo[d]thiazoles, and 1,2-disubstituted benzo[d]imidazoles. N-Heterocyclic carbene (NHC), generated in situ from easily available N-heterocyclic imidazolium salt with air as terminal oxidant, has successfully been utilized as a cheap and efficient catalyst for one-pot aerobic oxidative synthesis of 2-arylbenzo[d]oxazoles, 2-substituted
摘要 N-杂环卡宾(NHC)是由易获得的N-杂环咪唑盐以空气为末端氧化剂原位生成的,已成功地用作便宜且有效的一锅好氧氧化合成2-芳基苯并[ d ]恶唑的催化剂,2-取代的苯并[ d ]噻唑和1,2-二取代的苯并[ d ]咪唑。 N-杂环卡宾(NHC)是由易获得的N-杂环咪唑盐以空气为末端氧化剂原位生成的,已成功地用作便宜且有效的一锅好氧氧化合成2-芳基苯并[ d ]恶唑的催化剂,2-取代的苯并[ d ]噻唑和1,2-二取代的苯并[ d ]咪唑。
Enantioselective Copper‐Catalyzed Three‐Component Carboboronation of Allenes: Access to Functionalized Dibenzo [
<i>b,f</i>
][1,4]oxazepine Derivatives
(B2(Pin)2) to approach functionalized dibenzo[b,f][1,4]oxazepine derivatives is developed. The chiral products are obtained in up to 81% yield, >20:1 dr, and 98% ee when either a chiral diphosphine ligand or a chiral ferrocenyl‐based P,N‐ligand is used. Furthermore, the reaction exhibits reversed diastereoselectivities when the chiral diphosphine ligand and the chiral P,N‐ligand are used respectively.
作者:Liu Cai、Yu-Liang Pan、Li Chen、Jin-Pei Cheng、Xin Li
DOI:10.1039/d0cc05855f
日期:——
An efficient asymmetric allylation reaction of allylboronates with seven-membered cyclic imines, dibenzo[b,f][1,4]oxazepines, is described. The reaction, which is catalyzed by a Bi(OAc)3/CPA system, gives a range of chiral nitrogen-containing heterocycle structures in high yields and with good enantioselectivities. The conversion of these products to nitrogen-containing heterocycles is also demonstrated