1311291-91-4Relevant academic research and scientific papers
Lewis base organocatalyzed enantioselective hydrosilylation of 1,4-benzoxazines
Jiang, Yan,Liu, Li-Xin,Yuan, Wei-Cheng,Zhang, Xiao-Mei
, p. 1797 - 1800 (2012)
A chiral Lewis base organocatalyzed enantioselective hydrosilylation of 1,4-benzoxazines is presented. The reactions afforded various enantioenriched 3-substituted dihydro-2H-1,4-benzoxazines with high yields (up to 98%) in moderate enantioselectivities (up to 87% ee).
Method for preparing 3,4-dihydrobenzo[b][1,4]oxazine derivatives
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Paragraph 0073; 0075, (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.
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.
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
