使用(环辛二烯)铱氯化二聚物/(S)-SegPhos /碘{[Ir(COD)Cl] 2 /(S)-SegPhos实现对3-芳基2 H -1,4-苯并恶嗪的高度对映选择性氢化/ I 2 }体系作为催化剂,ee最高可达92%。3-styryl-2 H -1,4-苯并恶嗪衍生物还通过铱催化剂和Pd / C在两个连续的步骤中进行氢化,从而获得93-95%ee值。
A highlyefficient synthesis of novel spirocyclic benzoxazine‐indenes from benzoxazine and alkynes via iminedirected C–H activation/annulation using rhodium catalyst was reported. The methodology could be applied to various benzoxazines and alkynes, giving the corresponding spiro indenyl benzoxazine as spirocycle products in good yields.
First I2–K2CO3-promoted sequential C–N and C–O bond forming approach for one-pot synthesis of 1,4-benzoxazines
作者:Sunil K. Singh、Anil K. Bajpai、Rajesh Saini
DOI:10.1016/j.tetlet.2013.10.092
日期:2013.12
system for the one-potsynthesis of 3-aryl-2H-benz[1,4]oxazine viarapid CN and C–O bond formation. No by-product formation, operational simplicity, ambient temperature, and high yield (85–94%) are the attractive features of the envisaged reaction. The reported one-potsynthesis of 1,4-benzoxazine involves the application of I2–K2CO3 catalyst system for the first time and proceeds via in situ imine
已经发现,I 2 –K 2 CO 3组合是一种通过快速CN和C–O一锅合成3-芳基-2 H-苯并[1,4]恶嗪的有效,可重复使用和廉价的催化剂体系。键的形成。没有副产物的形成,操作简便,环境温度和高产率(85-94%)是预期反应的吸引人的特征。已报道的1,4-苯并恶嗪的一锅法合成首次涉及I 2 -K 2 CO 3催化剂体系的应用,并通过原位亚胺形成,随后进行分子内环转化级联反应进行。
Highly Enantioselective SPINOL-Derived Phosphoric Acid Catalyzed Transfer Hydrogenation of Diverse C=N-Containing Heterocycles
作者:Yiliang Zhang、Rong Zhao、Robert Li-Yuan Bao、Lei Shi
DOI:10.1002/ejoc.201500330
日期:2015.5
A highly efficient and enantioselectivehydrogenation of diversely substituted C=N-containing heterocyclic compounds such as 3-aryl-1,4-benzoxazines and 2-arylquinolines was experimentally explored by using 1,1′-spirobiindane-7,7′-diol-derived chiral phosphoric acids as the catalyst. This method provides straightforward access to the corresponding tetrahydroquinolines and dihydro-2H-1,4-benzothiazines
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Promoted hydrogenations of N-heterocycles with ammonia borane
作者:Fangwei Ding、Yiliang Zhang、Rong Zhao、Yanqiu Jiang、Robert Li-Yuan Bao、Kaifeng Lin、Lei Shi
DOI:10.1039/c7cc04709f
日期:——
A transition-metal-free method for the B(C6F5)3-promoted hydrogenations of N-heterocycles using ammonia borane under mild reaction conditions has been developed. The reaction affords a broad range of hydrogenated products in moderate to good yields. The enantioselective versions for the corresponding products were also investigated via our approach, showing good feasibility.
已开发出一种无过渡金属的方法,该方法使用硼烷氨在温和的反应条件下进行B(C 6 F 5)3促进的N-杂环加氢反应。该反应以中等至良好的产率提供了广泛的氢化产物。还通过我们的方法对相应产品的对映选择性进行了研究,显示出良好的可行性。