Results 21 to 30 of about 433,597 (216)

Synthesis of Chiral 1,4,2-Oxazaphosphepines

Molecules, 2015
Synthesis and structural characterization of 1,4,2-oxazaphosphepines is described. The 1,4,2-oxazaphosphepines were obtained from reaction of chiral 1,3-benzoxazines with dichlorophenylphosphine or triethyl phosphite.
Oscar Salgado-Escobar, Leticia Chavelas-Hernández, Blanca E. Domínguez-Mendoza, Irma Linzaga-Elizalde, Mario Ordoñez   +4 more
doaj   +1 more source

Studies on 1,3-benzoxazines. VII. Formation of diphenylpyrimidines by the reaction of 4-chloro-2H-1,3-benzoxazines with ethyl 3-aminobutyrate.

Chemical and Pharmaceutical Bulletin, 1982
AbstractDie 4‐Chlorbenzoxazine (I) reagieren mit β‐Aminobuttersäureester (II) unter Ringöffnung und Bildung von Pyrimidin‐Derivaten (III).
TACHIKAWA, RYUJI, WACHI, KAZUYUKI, TERADA, ATSUSUKE   +2 more
openaire   +2 more sources

Simple and Selective Synthesis of 1,3-Benzoxazine Derivatives

Oriental Journal Of Chemistry, 2012
A simple and selective synthesis of 1,3-benzoxazine-2,4-dione and 4-methylene-1,3benzoxazine-2-one derivatives is reported from the reaction of Schiff bases and triphosgene. The selective synthesis of those 1,3-benzoxazine derivatives were found to be dependent on the type of substituents present on the Schiff base.
Ali Abdullah Al-Qahtani, Turki M. Al-Turki, Ahmed Amine Mousa, Sara Abdullah Al-Mazroa, Hamad Z. Alkhathlan, M. Khan   +5 more
openaire   +1 more source

Enantioselective Desymmetrization of 3Substituted Oxetanes: An Efficient Access to Chiral 3,4-Dihydro2H1,4-benzoxazines

, 2021
Herein, we describe a versatile transition metal/oxidant free synthesis of the chiral 2H-1,4-benzoxazines through chiral phosphoric acid (CPA) catalyzed enantioselective desymmetrization of prochiral oxetanes (30 examples) in up to 99% yield and 99 ...
Ivana Císařová, Martin Nigríni, Jan Veselý (1843195), Martin Dračínský, Martin Nigríni (11751478), Viraj A. Bhosale, Jan Veselý, Martin Dračínský (1398268), Viraj A. Bhosale (11751475), Ivana Císařová (1580947)   +9 more
core   +1 more source

Enantioselective Desymmetrization of 3‑Substituted Oxetanes: An Efficient Access to Chiral 3,4-Dihydro‑2H‑1,4-benzoxazines

, 2021
Herein, we describe a versatile transition metal/oxidant free synthesis of the chiral 2H-1,4-benzoxazines through chiral phosphoric acid (CPA) catalyzed enantioselective desymmetrization of prochiral oxetanes (30 examples) in up to 99% yield and 99 ...
Jan Veselý (1843195), Martin Nigríni (11751478), Martin Dračínský (1398268), Viraj A. Bhosale (11751475), Ivana Císařová (1580947)   +4 more
core   +1 more source

Intrinsic self‐initiating thermal ring‐opening polymerization of 1,3‐benzoxazines without the influence of impurities using very high purity crystals

, 2017
A phenol/aniline type monofunctional benzoxazine monomer, PH-a, is synthesized and highly purified to study the intrinsic thermal ring-opening polymerization of benzoxazines without the influence of any impurity.
Lu Han, M. L. Salum, Kan Zhang, P. Froimowicz, H. Ishida   +4 more
semanticscholar   +1 more source

A Novel Synthesis of Enantiopure Octahydropyrrolo[3,4-b]pyrroles by Intramolecular [3 + 2] Dipolar Cycloaddition on Chiral Perhydro-1,3-benzoxazines

, 2016
Condensation of N-substituted glycines with chiral 3-allyl-2-formyl perhydro-1,3-benzoxazines forms an azomethine ylide that cyclizes to give octahydropyrrolo[3,4-b]pyrrole derivatives.
Javier Nieto (131402), Rafael Pedrosa (1748134), Celia Andrés (2520307), Laura de las Heras (1792828)   +3 more
core   +1 more source

Chiral Lewis Base Catalyzed Enantioselective Selenocyclization of 1,1-Disubstituted Alkenes: Asymmetric Synthesis of Selenium-Containing 4H‑3,1-Benzoxazines

, 2022
An enantioselective selenocyclization of 1,1-disubstituted alkenes was achieved for the first time, which is enabled by a novel combination of a chiral BINAM-derived sulfide and an achiral Lewis acid.
Yao Li (154923), Zhi-Min Chen (1668148), Lu Yu (74016), Yu-Xuan Huo (12710416), Xiao-Song Xue (1433848), Ren-Fei Cao (12073442)   +5 more
core   +1 more source

Nucleophilic Imines and Electrophilic o‑Quinone Methides, a Three-Component Assembly of Assorted 3,4-Dihydro‑2H‑1,3-benzoxazines

, 2019
A one-pot method for joining three separate components leading to an assortment of N-substituted 3,4-dihydro-2H-1,3-benzoxazines is described. The method involves the addition of a Grignard reagent to an o-OBoc salicylaldehyde in the presence of an imine.
Thomas R. R. Pettus (7399856), Kazaf KC Chan (11874279), Yuk Fai Wong (7399850), Derek Yang (7399853)   +3 more
core   +1 more source

Synthesis of Enantiopure 3-Azabicyclo[3.2.0]heptanes by Diastereoselective Intramolecular [2+2] Photocycloaddition Reactions on Chiral Perhydro-1,3-benzoxazines

, 2016
[2+2] photocycloadditions involving chiral 3-acryloyl-2-vinylperhydro-1,3-benzoxazines derived from (−)-8-aminomenthol are highly diastereoselective reactions.
Javier Nieto (131402), Rafael Pedrosa (1748134), Celia Andrés (2520307), Soledad del Pozo (2692753)   +3 more
core   +1 more source