Biomimetic asymmetric reduction of benzoxazinones and quinoxalinones using ureas as transfer catalysts
作者:Zi-Biao Zhao、Xiang Li、Mu-Wang Chen、Zongbao K. Zhao、Yong-Gui Zhou
DOI:10.1039/d0cc03091k
日期:——
Using ureas as transfer catalysts through hydrogen bonding activation, biomimetic asymmetric reduction of benzoxazinones and quinoxalinones with chiral and regenerable NAD(P)H models was described, giving chiral dihydrobenzoxazinones and dihydroquinoxalinones with high yields and excellent enantioselectivities. A key dihydroquinoxalinone intermediate of a BRD4 inhibitor was synthesized using biomimetic
Asymmetric hydrogenation of 3-methylbenz[b][1,4]oxazin-2-ones catalyzed by iridium complexes with phosphite-type ligands
作者:A. E. Lyubimov、D. B. Ozolin、V. A. Davankov
DOI:10.1007/s11172-016-1384-1
日期:2016.3
The chiral amidophosphite ligand in the iridium-catalyzed hydrogenation of 3-methylbenz[b][1,4]oxazin-2-ones in ethanol provides higher conversion and enantioselectivity than the phosphite ligand.
Regenerable Dihydrophenanthridine via Borane-Catalyzed Hydrogenation for the Asymmetric Transfer Hydrogenation of Benzoxazinones
作者:Bochao Gao、Wei Meng、Xiangqing Feng、Haifeng Du
DOI:10.1021/acs.orglett.2c01314
日期:2022.6.10
The highly enantioselective transfer hydrogenation of benzoxazinones with chiral phosphoric acids under H2 was successfully achieved, where boranes promoted the hydrogenation of phenanthridine for the regeneration of dihydrophenanthridine as the hydrogen donor. A variety of dihydrobenzoxazinones were obtained in high yields with up to 99% ee. The current work provides a promising solution to unreactive
成功实现了苯并恶嗪酮与手性磷酸在H 2下的高对映选择性转移加氢,其中硼烷促进菲啶的加氢以再生作为氢供体的二氢菲啶。以高达 99% ee 的高产率获得了多种二氢苯并恶嗪酮。目前的工作为受挫的路易斯对催化的不对称氢化提供了一种有前途的解决方案。
Manganese Pentacarbonyl Bromide as Regeneration Catalyst Enabled Biomimetic Asymmetric Reduction
Using readily available manganese pentacarbonyl bromide as a regeneration catalyst, biomimeticasymmetric reduction of imines including quinoxalinones, benzoxazinones, and benzoxazine has been successfully developed in the presence of transfer catalyst chiral phosphoric acids, providing the chiral amines with high yields and enantioselectivities.
METHOD OF ISOLATING ANTI-VIRAL INGREDIENTS FROM BAPHICACANTHUS CUSIA, COMPOSITIONS COMPRISING THEM AND THEIR MEDICAL USE
申请人:Macau University of Science and Technology
公开号:US20170281702A1
公开(公告)日:2017-10-05
The present invention provides a method of isolating at least one ingredient with anti-viral efficacy from
Baphicacanthus cusia.
The ingredient can be an alkaloid, a triterpenoid, a lignan, a phenylethanoid, a sesquiterpene lactone, or a flavonoid. Two new alkaloids are produced, which have not been previously reported. Moreover, the method isolates 12 compounds which could not or have not been previously isolated. A pharmaceutical composition includes the at least one ingredient and at least one pharmaceutical tolerable excipient. A method of treating a subject suffering from a viral disease includes administering at least one ingredient isolated from
Baphicacanthus cusia.