Syntheses and conformational analyses of new naphth[1,2-e][1,3]oxazino[3,2-c]quinazolin-13-ones

New insight into the anisotropic effects in solution-state NMR spectroscopy

“…NICS isosurfaces have been named isochemical shielding surfaces (ICSSs) by Klod and Kleinpeter. 16 The ICSSs have been applied to quantify and analyze anisotropic effects, [16][17][18][19][20][21][22] for stereochemistry determinations, [16][17][18][19][20][21] and to separate the anisotropic effect of functional groups from other inuences on proton chemical shis. [23][24][25][26] Merino et al 14 and Islas et al 15 calculated and graphically represented the "induced magnetic eld" of a molecule as the response to an external magnetic eld applied in a specic direction, and found such representations useful to get an information about electron delocalization.…”

Recent advances in the transformation reactions of the Betti base derivatives

“…Besides the conformations, both the congurations at C-7a and C-15 and the preferred rotamers of the 1-naphthyl substituent at C-15 were assigned, which allowed evaluation of the aryl substituent-dependent steric hindrance in this part of the molecules (Scheme 37). 62 In 2017, Baruah and co-workers developed visible light intramolecular cross dehydrogenative coupling of 1-aminoalkyl-2-naphthols 131 to 1,3-oxazines 132 in 53-78% yields using green LED lamp as the light source and eosin Y functions as photoredox catalyst in CH 3 CN at room temperature for 10-18 h. Organic photoredox catalyst eosin Y is used which is very cheap and non-hazardous. Moreover, aerial oxygen is used as the oxidant.…”

“…Besides the conformations, both the configurations at C-7a and C-15 and the preferred rotamers of the 1-naphthyl substituent at C-15 were assigned, which allowed evaluation of the aryl substituent-dependent steric hindrance in this part of the molecules (Scheme 37). 62…”

Synthesis and Conformational Behaviour of Enantiomeric Naphthoxazinoquinoxalinone Derivatives

“…On the other hand, by extending the modified Mannich reaction, 1-and 2-naphthols and their N-containing analogues were treated with a wide range of cyclic amines to furnish various aminonaphthol derivatives. These processes followed by ringclosing reactions led to the formation of naphth[1,2-e][1,3]oxazino [3,4-c] [1,3]benzoxazines, [3,4] naphth[1,2-e][1,3]oxazino- [3,4-c]quinazolines, [5] naphth[1,2-e][1, 3]oxazino [3,4-c]quinazolin-13-ones, [6] naphth[1,2-e][1,3]oxazino[4,3-a]isoquinolinones, [7] naphth [1,3]oxazino[3,2-a]benzazepines and naphth[1,3]oxazino[3,2-e]thienopyridine derivatives [8] (Figure 1).…”