20780-49-8Relevant articles and documents
Terpene Cyclizations inside a Supramolecular Catalyst: Leaving-Group-Controlled Product Selectivity and Mechanistic Studies
Zhang, Qi,Catti, Lorenzo,Pleiss, Jürgen,Tiefenbacher, Konrad
supporting information, p. 11482 - 11492 (2017/08/30)
The tail-to-head terpene cyclization is arguably one of the most complex reactions found in nature. The hydrogen-bond-based resorcinarene capsule represents the first man-made enzyme-like catalyst that is capable of catalyzing this reaction. Based on noncovalent interactions between the capsule and the substrate, the product selectivity can be tuned by using different leaving groups. A detailed mechanistic investigation was performed to elucidate the reaction mechanism. For the cyclization of geranyl acetate, it was found that the cleavage of the leaving group is the rate-determining step. Furthermore, the studies revealed that trace amounts of acid are required as cocatalyst. A series of control experiments demonstrate that a synergistic interplay between the supramolecular capsule and the acid traces is required for catalytic activity.
Visible-Light-Promoted Activation of Unactivated C(sp3)-H Bonds and Their Selective Trifluoromethylthiolation
Mukherjee, Satobhisha,Maji, Biplab,Tlahuext-Aca, Adrian,Glorius, Frank
supporting information, p. 16200 - 16203 (2016/12/27)
Selective functionalization of ubiquitous C(sp3)-H bonds using visible light is a highly challenging yet desirable goal in organic synthesis. The development of such processes relies on both rational design and serendipitous discoveries from innovative tools such as screening technologies. Applying a mechanism-based screening strategy, we herein report photoredox-mediated hydrogen atom transfer catalysis for the selective activation of otherwise unactivated C(sp3)-H bonds, followed by their trifluoromethylthiolation, which has high potential as a late-stage functionalization tool. The generality of this method is exhibited through incorporation of the trifluoromethylthio group in a large number of C(sp3)-H bonds with high selectivity without the need for an excess of valuable substrate.
Selective oxidation of unactivated C-H bonds by supramolecular control
Fung, Yat-Sing,Yan, Siu-Cheong,Wong, Man-Kin
experimental part, p. 3122 - 3130 (2012/05/07)
Efficient methods for dioxirane-based selective C-H bond oxidation by supramolecular control in H2O have been developed. With β-cyclodextrin as the supramolecular host, site-selective oxidation of the terminal over the internal tertiary C-H bond of 3,7-dimethyloctyl esters 3a-c was achieved. In addition, β-cyclodextrin selectively enhanced the C-H bond oxidation of cumene in a mixture of cumene and ethyl benzene in H2O. Through 1H NMR studies, the selectivity in C-H bond oxidation could be attributed to the inclusion complex formation between β-cyclodextrin and the substrates. The Royal Society of Chemistry 2012.
