70310-27-9Relevant academic research and scientific papers
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
, p. 3381 - 3386 (2013)
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
Remarkable Ligand Effect on Rh-Catalyzed C-H-Active [3 + 2] Annulation of Ketimines and Alkynes
Fang, Yong,Luo, Yunfei,Shi, Yan,Wu, Xiang,Yang, Xiaoming,Zhao, Xu,Zhu, Chengfeng
supporting information, (2020/06/24)
Externally added ligands were first found to have a significant impact on the Rh-catalyzed C-H-active [3 + 2] annulation of ketimines and alkynes. Olefin ligands have shown remarkable promotion effect for this reaction. The olefin promoted the reaction by
A metal-free hydrogenation of 3-substituted 2H-1,4-benzoxazines
Wei, Simin,Feng, Xiangqing,Du, Haifeng
, 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.
Method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives
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Paragraph 0068; 0069, (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.
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.
An organocatalyst bearing stereogenic carbon and sulfur centers as an efficient promoter for enantioselective hydrosilylation of 1,4-benzooxazines
Liu, Xiang-Wei,Wang, Chao,Yan, Yan,Wang, Yong-Qiang,Sun, Jian
, p. 6276 - 6280 (2013/07/26)
The efficient and enantioselective hydrosilylation of 3-aryl-1,4- benzooxazines was achieved using an l-phenyl alanine derived new Lewis base catalyst bearing stereogenic carbon and sulfur centers. In the presence of 2 mol % of catalyst, a broad range of 3-aryl-1,4-benzooxazines were hydrosilylated to afford the corresponding chiral 3-aryl-3,4-dihydro-2H-1,4-benzooxazine products with good to high yields (66-98%) and enantioselectivities (70-99% ee). This method provides an alternative approach with great practical application potential to access chiral 3-aryl-3,4-dihydro-2H-1,4-benzooxazines.
A new convenient method for the synthesis of 2H-1,4-benzoxazine derivatives from nitroketones via intramolecular reductive cyclization
Joung, Meyoung Ju,Ahn, Jin Hee,Kim, Hoe Moon,Kim, Kee Won,Kang, Jae Hoon,Lee, Seok Joon,Yoon, Nung Min
, p. 1065 - 1069 (2007/10/03)
Potentially bioactive 2H-1,4-benzoxazine derivatives could be conveniently prepared in one step from the corresponding nitroketones using 10% palladium on carbon with triethylamine in the presence of hydrogen (Pd/C-TEA-H2) system. Several other
SYNTHESIS OF 3-ARYLCOUMARINS, 2-AROYLBENZOFURANS AND 3-ARYL-2H-1,4-BENZOXAZINES UNDER PHASE-TRANSFER CATALYSIS CONDITIONS
Sabitha, G.,Rao, A. V. Subba
, p. 341 - 354 (2007/10/02)
The synthesis of 3-arylcoumarins, 2-aroylbenzofurans and 3-aryl-2H-1,4-benzoxazines under phase transfer catalysis conditions is described.
