Cooperative Hydrogen-Bonding Effects in Silanediol Catalysis
作者:Ngon T. Tran、Sean O. Wilson、Annaliese K. Franz
DOI:10.1021/ol202971m
日期:2012.1.6
cooperative hydrogen-bonding effects and SiOH-acidification is described for silanediolcatalysis. NMR binding, X-ray, and computational studies provide support for a unique dimer resulting from silanediol self-recognition. The significance of this cooperative hydrogen-bonding is demonstrated using novel fluorinated silanediol catalysts for the addition of indoles and N,N-dimethyl-m-anisidine to trans-β-nitrostyrene
H-Bonding Organocatalysed Friedel-Crafts Alkylation of Aromatic and Heteroaromatic Systems with Nitroolefins
作者:Raquel P. Herrera、Alfredo Ricci、Gabriella Dessole
DOI:10.1055/s-2004-832844
日期:——
Catalytic amounts (10 mol%) of bis-arylureas and -thioureas promote the Friedel-Crafts alkylation with nitroolefins of aromatic and heteroaromatic N-containing derivatives. A sizeable improvement of the yields is noticed on running the reactions in the absence of solvent. When applied to indoles this protocol provides in good to excellent yields and with high selectivity the corresponding Michael adducts
2-Aminopyridinium ions were found to activate nitroalkenes toward conjugate addition of heteroaromatic compounds with low catalyst loadings and the Diels-Alder reaction with the periselectivity opposite to that observed with metal Lewis acids, raising the possibility that a 2-aminopyridinium core might be a promising catalaphore for the asymmetric catalyst design.
Supramolecular Relay-Control of Organocatalysis with a Hemithioindigo-Based Molecular Motor
作者:Kerstin Grill、Henry Dube
DOI:10.1021/jacs.0c09519
日期:2020.11.11
Integration of individual molecular components such as molecular motors or switches into larger meta-functional systems represents a current challenge at the forefront of molecular machine research. Here we present a modular supramolecular approach to relay the photoinduced geometry changes of a hemithioindigo based molecular motor into catalytic efficiency of a chemical reaction. Using the intrinsic chemical