The Thermal Benzoxazinone-Benzoxazole Conversion, a Reexecution of a Mass Spectrometric Decay by Thermolysis
作者:Werner Reichen
DOI:10.1002/hlca.19770600121
日期:1977.1.26
The base peak in the mass spectrum of several 1,4,2-benzoxazinone derivatives 1a–f (cf. Scheme 1 and the Table) suggests a clean carbon monoxide elimination leading to benzoxazole radical cations 2a–f. This benzoxazinone-benzoxazoleconversion can be reproduced quantitatively by flash vacuum thermolysis.
Addition of catechol to methyl propiolate or ethyl phenylpropiolate in the presence of Ph3P leads to methyl 2-(1,3-benzodioxol-2-yl)acetate or 3-(1-phenylmethylidene)-1,4-benzodioxin-2-one. 2-Aminophenols react with alkyl propiolates in the presence of Ph3P to produce a nearly 1:1 mixture of 3-methyl-2H-1,4-benzoxazin-2-one derivatives and methyl (E)-3-(2-aminophenoxy)-2-propenoates.
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.