32683-64-0Relevant academic research and scientific papers
Rhodium-Catalyzed Spiro Indenyl Benzoxazine Synthesis via C-H Activation/Annulation of 3-Aryl-2H-Benzo[b][1,4]oxazines and Alkynes
Tan, Heng,Laishram, Ronibala Devi,Zhang, Xuexin,Shi, Guangrui,Li, Kangkui,Chen, Jingchao
supporting information, p. 4542 - 4546 (2020/07/04)
The rhodium (III)-catalyzed annulation of 3-Aryl-2H-Benzo[b][1,4]oxazines with alkynes via C–H activation has been developed. This reaction afforded a series of spiro indenyl benzoxazine in high yields under mild reaction condition with good functional group tolerance.
Method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives
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Paragraph 0070; 0072, (2016/10/10)
The invention provides a method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives. The method comprises the following step: carrying out reduction reaction on [b][1,4]oxazines in the presence of hydrogen gas by using B(C6F5)3 as a catalyst to obtain the mixture containing the 3,4-dihydrobenzo[b][1,4]oxazines disclosed as Formula I. Benzo[b][1,4]oxazines in different structures are used as a substrate to synthesize the benzo[b][1,4]oxazines at high yield by using the B(C6F5)3 as the catalyst. The method has the advantages of cheap and accessible raw materials, high reaction activity, no participation of transition metals and wide substrate application range, and has huge industrialization potential.
A metal-free hydrogenation of 3-substituted 2H-1,4-benzoxazines
Wei, Simin,Feng, Xiangqing,Du, Haifeng
supporting information, p. 8026 - 8029 (2016/09/09)
A metal-free hydrogenation of 3-substituted 2H-1,4-benzoxazines has been successfully realized with 2.5 mol% of B(C6F5)3 as a catalyst to furnish a variety of 3,4-dihydro-2H-1,4-benzoxazines in 93-99% yields. Up to 42% ee was also achieved for the asymmetric hydrogenation with the use of a chiral diene and HB(C6F5)2.
Highly enantioselective spinol-derived phosphoric acid catalyzed transfer hydrogenation of diverse C=N-containing heterocycles
Zhang, Yiliang,Zhao, Rong,Bao, Robert Li-Yuan,Shi, Lei
supporting information, p. 3344 - 3351 (2015/05/20)
A highly efficient and enantioselective hydrogenation 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 in high yields (85-99%) with excellent enantioselectivities (91-99%). The attractive features of this procedure, which include mild reaction conditions, operational simplicity, relatively low catalyst loading (1 mol-%), and high levels of enantioselectivities, make it a useful approach for the practical synthesis of optically active nitrogen-containing aromatic heterocycles.
4,5-Dihydropyrrolo[1,2-a]quinoxalines: A tunable and regenerable biomimetic hydrogen source
Chen, Zhang-Pei,Chen, Mu-Wang,Guo, Ran-Ning,Zhou, Yong-Gui
supporting information, p. 1406 - 1409 (2014/04/03)
A series of tunable and regenerable biomimetic hydrogen sources, 4,5-dihydropyrrolo[1,2-a]quinoxalines, have been synthesized and applied in biomimetic asymmetric hydrogenation of 3-aryl-2H-benzo[b][1,4]oxazines and 1-alkyl-3-aryl-quinoxalin-2(1H)-ones, providing the chiral amines with up to 92% and 89% ee, respectively.
[Ir(P-OP)]-catalyzed asymmetric hydrogenation of diversely substituted C=N-containing heterocycles
Nunez-Rico, Jose Luis,Vidal-Ferran, Anton
supporting information, p. 2066 - 2069 (2013/06/04)
Iridium(I) complexes of enantiomerically pure phosphine-phosphite ligands ([Ir(Cl)(cod)(P - OP)]) efficiently catalyze the enantioselective hydrogenation of diverse C=N-containing heterocyclic compounds (benzoxazines, benzoxazinones, benzothiazinones, and quinoxalinones; 25 examples, up to 99% ee). A substrate-to-catalyst ratio as high as 2000:1 was reached.
Direct organocatalytic asymmetric mannich addition of 3-substituted-2H-1,4- benzoxazines: Access to tetrasubstituted carbon stereocenters
Wang, You-Qing,Zhang, Yongna,Pan, Kun,You, Junxiong,Zhao, Jin
supporting information, p. 3381 - 3386 (2013/12/04)
3-Substituted-2H-1,4-benzoxazines undergo a highly enantioselective direct Mannich reaction with acetone in the presence of an L-proline catalyst at room temperature. The corresponding N-heterocycles with α-tetrasubstituted carbon stereocenters were obtai
Iridium-catalyzed asymmetric hydrogenation of 3-substituted 2H-1,4-benzoxazines
Gao, Kai,Yu, Chang-Bin,Wang, Duo-Sheng,Zhou, Yong-Gui
experimental part, p. 483 - 488 (2012/05/04)
The highly enantioselective hydrogenation of 3-aryl-2H-1,4-benzoxazines was achieved using the (cyclooctadiene)iridium chloride dimer/(S)-SegPhos/iodine {[Ir(COD)Cl]2/(S)-SegPhos/I2} system as catalyst with up to 92% ee. The 3-styryl
