21222-04-8Relevant articles and documents
Conformational analysis and interpretation of ν(OH) bands in the IR spectra of 1′-hydroxyethyl derivatives of 1,4-benzo- and 5,8-dihydroxy-1,4-naphthoquinones: A DFT study
Glazunov,Berdyshev,Pokhilo,Anufriev
, p. 663 - 674 (2009)
Detailed conformational analysis of the molecule of 1′-hydroxyethyl- 1,4-benzoquinone (3) by the B3LYP/cc-pVTZ method revealed predominance of rotamers with the free 1′-OH group in the gas phase. B3LYP/cc-pVTZ calculations with inclusion of solvent (cyclohexane) effect in the framework of the polarizable continuum model predict an increase in the percentage of such rotamers compared to the corresponding gas-phase values. The results obtained are in qualitative agreement with the experimentally observed pattern of ν(OH) bands in the IR spectrum of compound 3 in cyclohexane (hexane) solution. Conformational analysis, in cluding tautomerism and rotamerism, of 2-ethyl-1′,5,8-trihydroxy-1,4-naphthoquinone (2) was performed by the B3LYP method with the 6-31G(d), 6-311G(d), 6-311G(d,p), and cc-pVDZ basis sets. The most abundant tautomeric form of compound 2 is form A in which the substituent bearing 1 '-OH group is in the quinonoid nucleus. In the gas phase, the percentage of all rotamers in form A is about 86% (among them, the proportion of rotamers with the free 1'-OH group is more than 60%). The main reason for splitting of the v(OH) bands in the IR spectra of compounds 2 and 3 in solutions in nonpolar solvents is the equilibrium between rotamers with a relatively weak intramolecular hydrogen bond between the 1′-OH group and the carbonyl group and those having no this bond.
Application of E1cB Elimination in Asymmetric Organocatalytic Cascade Reactions to Construct Polyheterocyclic Compounds
You, Zhi-Hao,Chen, Ying-Han,Tang, Yu,Liu, Yan-Kai
supporting information, p. 8358 - 8363 (2019/10/16)
By introducing a carbon functionality at 2-position of chromane, the formal asymmetric functionalization of the 3-position of 2-substituted chromane has been realized via a highly chemo-, regio-, and stereoselective organocatalytic cascade reaction in a sequential one-pot manner involving an E1cB mechanism governed ring-opening process. Critical to our success was the design of a chiral dipeptide-based bifunctional acid-base organocatalyst, which exhibited high catalytic activity at low catalyst loading (1-0.1 mol %), leading to biologically interesting polyheterocyclic compounds.
Synthesis, antiproliferative, and c-Src kinase inhibitory activities of 4-oxo-4H-1-benzopyran derivatives
Chand, Karam,Tiwari, Rakesh K.,Kumar, Sumit,Shirazi, Amir Nasrolahi,Sharma, Sweta,Van Der Eycken, Erik V.,Parmar, Virinder S.,Parang, Keykavous,Sharma, Sunil K.
, p. 562 - 572 (2015/03/30)
A new class of 4-oxo-4H-1-benzopyran derivatives were synthesized and their antiproliferative activity examined against a panel of three human cancer cell lines, that is, breast carcinoma (MDA-MB-468), ovarian adenocarcinoma (SK-OV-3), and colorectal adenocarcinoma (HT-29). Two compounds, that is, 3-hexyl-7,8-dihydroxy-4-oxo-4H-1-benzopyran and (E)-ethyl 3-(7-methoxy-4-oxo-4H-1-benzopyran-3-yl)acrylate were found to be potent against all three cancer cell lines studied at 50 μM concentration. Also, the inhibitory potency of the compounds was evaluated against active Src kinase. A few of these compounds exhibited modest Src kinase inhibitory activity (IC50 = 52-57 μM). Structure-activity relationship studies with respect to the nature and position of substituents on the lead compounds could be further exploited for the design and development of more potent antiproliferative agents and/or Src kinase inhibitors.
