21947-71-7Relevant articles and documents
Molecular conformational analysis, vibrational spectra, NBO analysis and first hyperpolarizability of (2E)-3-phenylprop-2-enoic anhydride based on density functional theory calculations
Sheena Mary,Raju,Panicker, C. Yohannan,Al-Saadi, Abdulaziz A.,Thiemann, Thies,Van Alsenoy, Christian
, p. 638 - 646 (2014)
The conformational behavior and structural stability of (2E)-3-phenylprop-2-enoic anhydride were investigated by using density functional theory. Seventeen possible stable conformations of the title compound were determined and verified with their calcula
Photocatalytic Oxidative [2+2] Cycloelimination Reactions with Flavinium Salts: Mechanistic Study and Influence of the Catalyst Structure
Hartman, Tomá?,Reisnerová, Martina,Chudoba, Josef,Svobodová, Eva,Archipowa, Nataliya,Kutta, Roger Jan,Cibulka, Radek
, p. 373 - 386 (2021/02/01)
Flavinium salts are frequently used in organocatalysis but their application in photoredox catalysis has not been systematically investigated to date. We synthesized a series of 5-ethyl-1,3-dimethylalloxazinium salts with different substituents in the positions 7 and 8 and investigated their application in light-dependent oxidative cycloelimination of cyclobutanes. Detailed mechanistic investigations with a coumarin dimer as a model substrate reveal that the reaction preferentially occurs via the triplet-born radical pair after electron transfer from the substrate to the triplet state of an alloxazinium salt. The very photostable 7,8-dimethoxy derivative is a superior catalyst with a sufficiently high oxidation power (E=2.26 V) allowing the conversion of various cyclobutanes (with Eox up to 2.05 V) in high yields. Even compounds such as all-trans dimethyl 3,4-bis(4-methoxyphenyl)cyclobutane-1,2-dicarboxylate can be converted, whose opening requires a high activation energy due to a missing pre-activation caused by bulky adjacent substituents in cis-position.
Isothiourea-Catalyzed Atroposelective N-Acylation of Sulfonamides
Ong, Jun-Yang,Ng, Xiao Qian,Lu, Shenci,Zhao, Yu
supporting information, p. 6447 - 6451 (2020/09/02)
We report herein an atroposelective N-acylation of sulfonamides using a commercially available isothiourea catalyst, (S)-HBTM, with a simple procedure. The N-sulfonyl anilide products can be obtained in good to high enantiopurity, which represents a new axially chiral scaffold. The application of the product as a chiral iodine catalyst is also demonstrated for the asymmetric α-oxytosylation of propiophenone.