IPy2BF4-Mediated Rearrangements of 1,2-Difunctionalized Compounds and Olefins
作者:Francisco J. Fañanás、Mónica Álvarez-Pérez、Félix Rodríguez
DOI:10.1002/chem.200500070
日期:2005.10.7
Acetal derivatives are easily obtained from 1,2-difunctionalizedcompounds by a new reaction mediated by IPy2BF4 with a mechanism based on a 1,2-migration of aryl or alkyl groups. A new oxidative rearrangement reaction of olefins is also described. Moreover, when this metal-free protocol is applied to cyclic olefins, interesting ring-contraction reactions are observed. The new methodologies described
Photochemical synthesis of acetals utilizing Schreiner's thiourea as the catalyst
作者:Nikoleta Spiliopoulou、Nikolaos F. Nikitas、Christoforos G. Kokotos
DOI:10.1039/d0gc01135e
日期:——
in Organic Chemistry for both synthetic and biological puproses. Herein, we report a mild, inexpensive and green photochemical protocol, where Schreiner's thiourea (N,N′-bis[3,5-bis(trifluoromethyl)-phenyl]-thiourea) is utilized as the catalyst and cheap household lamps as the light source. A variety of aromatic and aliphatic aldehydes were converted into acetals in good to high yields (23 examples
Photo-organocatalytic synthesis of acetals from aldehydes
作者:Nikolaos F. Nikitas、Ierasia Triandafillidi、Christoforos G. Kokotos
DOI:10.1039/c8gc03605e
日期:——
developed. Utilizing thioxanthenone as the photocatalyst and inexpensive household lamps as the light source, a variety of aromatic and aliphatic aldehydes have been converted into acyclic and cyclic acetals in highyields. The reaction mechanism was extensively studied.
Hydrophobic Acetal and Ketal Derivatives of Mannopeptimycin-α and Desmethylhexahydromannopeptimycin-α: Semisynthetic Glycopeptides with Potent Activity Against Gram-Positive Bacteria
作者:Russell G. Dushin、Ting-Zhong Wang、Phaik-Eng Sum、Haiyin He、Alan G. Sutherland、Joseph S. Ashcroft、Edmund I. Graziani、Frank E. Koehn、Patricia A. Bradford、Peter J. Petersen、Karen L. Wheless、David How、Nancy Torres、Eileen B. Lenoy、William J. Weiss、Stanley A. Lang、Steven J. Projan、David M. Shlaes、Tarek S. Mansour
DOI:10.1021/jm049765y
日期:2004.7.1
The effect of introducing hydrophobic groups onto the disaccharide portion of the mannopeptimycins has been examined. Under acid-catalyzed conditions dimethylacetals and ketals react on the terminal mannose of the disaccharide moiety of mannopeptimycin-alpha and the cyclohexylalanyl analogue 2. The preferentially formed monofunctionalized 4,6-acetals and -ketals display potent antibacterial activities