1311291-96-9Relevant academic research and scientific papers
Kinetic Resolution by Lithiation: Highly Enantioselective Synthesis of Substituted Dihydrobenzoxazines and Tetrahydroquinoxalines
El-Tunsi, Ashraf,Carter, Nicholas,Yeo, Song-Hee,Priest, Joshua D.,Choi, Anthony,Kobras, Carolin M.,Ndlovu, Soneni,Proietti Silvestri, Ilaria,Fenton, Andrew K.,Coldham, Iain
, p. 355 - 368 (2021/11/13)
Kinetic resolution provided a highly enantioselective method to access a range of 3-aryl-3,4-dihydro-2H-1,4-benzoxazines using n-butyllithium and the chiral ligand sparteine. The enantioenrichment remained high on removing the tert-butoxycarbonyl (Boc) protecting group. The intermediate organolithium undergoes ring opening to an enamine. The kinetic resolution was extended to give enantiomerically enriched substituted 1,2,3,4-tetrahydroquinoxalines and was applied to the synthesis of an analogue of the antibiotic levofloxacin that was screened for its activity against the human pathogen Streptococcus pneumoniae.
First I2-K2CO3-promoted sequential C-N and C-O bond forming approach for one-pot synthesis of 1,4-benzoxazines
Singh, Sunil K.,Bajpai, Anil K.,Saini, Rajesh
, p. 7132 - 7135 (2013/12/04)
I2-K2CO3 combination has been found to be an efficient, reusable, and inexpensive catalyst system for the one-pot synthesis of 3-aryl-2H-benz[1,4]oxazine via rapid CN and C-O bond formation. No by-product formation, operat
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.
Lewis base organocatalyzed enantioselective hydrosilylation of 1,4-benzoxazines
Jiang, Yan,Liu, Li-Xin,Yuan, Wei-Cheng,Zhang, Xiao-Mei
, p. 1797 - 1800 (2012/08/29)
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).
