108266-75-7Relevant academic research and scientific papers
Experimental and theoretical insights in the alkene-arene intramolecular π-stacking interaction
Corne, Valeria,Sarotti, Ariel M.,De Arellano, Carmen Ramirez,Spanevello, Rolando A.,Suárez, Alejandra G.
, p. 1616 - 1623 (2016)
Chiral acrylic esters derived from biomass were developed as models to have a better insight in the aryl-vinyl π-stacking interactions. Quantum chemical calculations, NMR studies and experimental evidences demonstrated the presence of equilibriums of at least four different conformations: π-stacked and face-to-edge, each of them in an s-cis/s-trans conformation. The results show that the stabilization produced by the π-π interaction makes the π-stacked conformation predominant in solution and this stabilization is slightly affected by the electron density of the aromatic counterpart.
Acyloxyborane: An Activating Device for Carboxylic Acids
Furuta, Kyoji,Miwa, Yoshikazu,Iwanaga, Kiyoshi,Yamamoto, Hisashi
, p. 6254 - 6255 (1988)
We chose α,β-unsaturated acids and investigated the reactivity of their borane adducts in Diels-Alder reactions.The reaction did proceed smoothly and has been found to be a useful method for synthesis of carboxylic acids.
Solvent-free Diels-Alder reactions of in situ generated cyclopentadiene
Huertas, David,Florscher, Melinda,Dragojlovic, Veljko
, p. 91 - 95 (2009)
A solvent-free Diels-Alder reaction was carried out by heating a mixture of dicyclopentadiene and a dienophile. Cyclopentadiene, formed in situ, reacted with the dienophile in a thermodynamically controlled reaction. Besides being solvent-free, the descri
Total Syntheses of Sandalwood Fragrances: (Z)- and (E)-β-Santalol and Their Enantiomers, ent-β-Santalene
Krotz, Achim,Helmchen, Guenter
, p. 537 - 540 (1990)
Via asymmetric Diels-Alder reactions, large scale preparations of enantiomerically pure norbornane-2-carboxylic acids were carried out.Oxidative degradation furnished 2-norbornanone and 3-methyl-2-norbornanone which gave the title compounds via stereoselective alkylations, subsequent Wittig reactions and reductions.
Synthesis of a Chiral Auxiliary Family from Levoglucosenone and Evaluation in the Diels-Alder Reaction
Klepp, Julian,Sumby, Christopher J.,Greatrex, Ben W.
, p. 1441 - 1446 (2018)
A new family of chiral auxiliaries has been developed based on the lignocellulosic biomass pyrolysis product levoglucosenone. A promising single stereoisomer with an alcohol and π-stacking phenyl substituents was prepared in excellent yield in two steps from dihydrolevoglucosenone without chromatography on >50 g scale. Acrylate esters prepared from the auxiliaries underwent diastereoselective Lewis acid promoted Diels-Alder reactions with cyclopentadiene (endo / exo 98:2, endo d. r. up to 98:2), dimethylbutadiene (d.r. 93:7), and isoprene (d.r. > 98:2).
A convenient practical method for the preparation of ( - )-(1S,2S)-5-norbornene-2-carboxylic acid, incorporating efficient recovery of the chiral auxiliary D-pantolactone
Chang, HeXi,Zhou, Li,McCargar, Robert D.,Mahmud, Tanvir,Hirst, Ian
, p. 289 - 291 (1999)
A convenient practical method was developed for the preparation of enantiomerically pure ( - )-(1S,2S)-5-norbornene-2-carboxylic acid, wherein the chiral auxiliary D-pantolactone was recovered efficiently.
Broad-spectrum enantioselective Diels-Alder catalysis by chiral, cationic oxazaborolidines
Ryu, Do Hyun,Lee, Thomas W.,Corey
, p. 9992 - 9993 (2002)
The cationic chiral Lewis acids 1 and 2, generated by triflic acid protonation of the corresponding neutral oxazaborolidines, serve as excellent catalysts for Diels-Alder addition of cyclopentadiene to a wide variety of dienophiles. Adducts have been obta
Ion Conducting ROMP Monomers Based on (Oxa)norbornenes with Pendant Imidazolium Salts Connected via Oligo(oxyethylene) Units and with Oligo(ethyleneoxy) Terminal Moieties
Price, Terry L.,Choi, U Hyeok,Schoonover, Daniel V.,Arunachalam, Murugan,Xie, Renxuan,Lyle, Steven,Colby, Ralph H.,Gibson, Harry W.
, p. 1371 - 1388 (2019)
A matrix of 22 two-armed norbornene-based imidazolium TFSI monomers (8) was synthesized to determine the optimal structure in terms of single ion conductivity. For the chain tethering the imidazolium ring to the norbornene ring three or four oxyethylene units are optimal. A terminal group of two ethyleneoxy units was optimal. NMR studies indicated that both the tether oxyethylene units and the terminal ethyleneoxy units interact with the imidazolium cation via hydrogen bonding. 8r (X = 4, Y = 2) exhibited a conductivity of 9.57 × 10-5 S/cm at 25 °C and a Tg of -46 °C. Low Tg values do not correlate with higher conductivity as a result of the H-bonding interactions. Stability toward autopolymerization and reasonable conductivities provide an acceptable platform for ion conducting ROMP polymers. Four one-armed norbornene-based imidazolium TFSI monomers (15) were prepared with tetra(ethyleneoxy) linkers/spacers and variable terminal groups. All of these exhibited low Tgs (10-4 S/cm, the highest being 4.39 × 10-4 S/cm for 15c (Tg = -69 °C), the analogue of 8r, providing hope for outstanding polymers. Three oxanorbornene-based two-armed imidazolium TFSI monomers (18) were prepared with varied linkers and terminal groups. 18b possesses a room temperature conductivity of 1.2 × 10-4 S/cm, again augering well for polymers derived therefrom by ROMP.
Fructose-derived ionic liquids: Recyclable homogeneous supports
Handy, Scott T.,Okello, Maurice
, p. 8399 - 8402 (2003)
A new homogeneous support has been developed that is based on a fructose-derived ionic liquid. It has been applied to the preparation of a series of supported Diels-Alder adducts. The cleavage of these adducts from the ionic liquid has resulted in some interesting observations regarding the base stability of imidazolium cations. Using a transesterification cleavage, the ionic support can be recovered and recycled.
Amphiphilic Bottlebrush Block Copolymers: Analysis of Aqueous Self-Assembly by Small-Angle Neutron Scattering and Surface Tension Measurements
Alaboalirat, Mohammed,Qi, Luqing,Arrington, Kyle J.,Qian, Shuo,Keum, Jong K.,Mei, Hao,Littrell, Kenneth C.,Sumpter, Bobby G.,Carrillo, Jan-Michael Y.,Verduzco, Rafael,Matson, John B.
, p. 465 - 476 (2019)
A systematic series of 16 amphiphilic bottlebrush block copolymers (BCPs) containing polystyrene and poly(N-acryloylmorpholine) (PACMO) side chains were prepared by a combination of atom-transfer radical polymerization (ATRP), photoiniferter polymerization, and ring-opening metathesis polymerization (ROMP). The grafting-through method used to prepare the polymers enabled a high degree of control over backbone and side-chain molar masses for each block. Surface tension measurements on the self-assembled amphiphilic bottlebrush BCPs in water revealed an ultralow critical micelle concentration (cmc), 1-2 orders of magnitude lower than linear BCP analogues on a molar basis, even for micelles with >90% PACMO content. Combined with coarse-grained molecular dynamics simulations, fitting of small-angle neutron scattering traces (SANS) allowed us to evaluate solution conformations for individual bottlebrush BCPs and micellar nanostructures for self-assembled macromolecules. Bottlebrush BCPs showed an increase in anisotropy with increasing PACMO content in toluene-d8, which is a good solvent for both blocks, reflecting an extended conformation for the PACMO block. SANS traces of bottlebrush BCPs assembled into micelles in D2O, a selective solvent for PACMO, were fitted to a core-shell-shell model, suggesting the presence of a partially hydrated inner shell. Results showed an average micelle diameter of 40 nm with combined shell diameters ranging from 16 to 18 nm. A general trend of increased stability of micelles (i.e., resistance to precipitation) was observed with increases in PACMO content. These results demonstrate the stability of bottlebrush polymer micelles, which self-assemble to form spherical micelles with ultralow (70 nmol/L) cmc's across a broad range of compositions.
