2049-96-9Relevant articles and documents
CH-π Interaction as an Important Driving Force of Host-Guest Complexation. Further Evidence for the Selective Incorporation of Alkyl Groups in the Polyhydroxy Aromatic Cavity of Calix[4]resorcarene Host
Kikuchi, Yasuaki,Aoyama, Yasuhiro
, p. 217 - 220 (1996)
The complexation of a calix[4]resorcarene host (2,8,14,20-tetraundecylcalix[4]arene-4,6,10,12,16,18,22,24-octol) with borneol in benzene or alkylbenzene was investigated by circular dichroism (CD) spectroscopy. The binding constants are dramatically solvent-dependent and decrease with respect to the substituents on the benzene ring in the order H>methyl>ethyl>propyl>butyl. The complexation of the same host with alkyl benzoates in limonene as a chiral hydrocarbon solvent was readily monitored by following their competitive inhibition effects on the CD intensities, reflecting the chiral host-solvent interaction. The binding constants for alkyl benzoates were again highly dependent on the alkyl groups, and changed in the order decylhexylmethylpropyl≈pentyl?butyl. There is thus an optimal chain length at butyl. These results provide further evidence for the selective incorporation of alkyl groups in the polyhydroxy aromatic cavity of the host.
Erratum: Ruthenium-catalyzed C-H hydroxylation in aqueous acid enables selective functionalization of amine derivatives (Journal of the American Chemical Society (2017) 139:28 (9503-9506) DOI: 10.1021/jacs.7b05469)
Mack, James B.C.,Gipson, John D.,Du Bois,Sigman, Matthew S.
supporting information, p. 3016 - 3016 (2021/03/01)
Page 9504. The structure of product 3cc in Table 2 was found to be mis-assigned. We thank Prof. Phil Baran and Dr. Rafael Navratil for bringing this error to our attention. The correct structure contains an additional benzylic alcohol at the C-9 position of the steroid (3cc′, shown below). With the accompanying change in molecular weight, the isolated yield is 29%. Supporting Information. The incorrect structure and yield also appeared on pages S20 and S84 in the SI. Given this, the HRMS entry on page S20 should read as follows: “HRMS (ESI-TOF) m/z calcd for C19H18F3O5S+ (M-O+Na)+ 415.0822, found 415.0857”. The complete corrected SI is provided here.
LiHMDS: Facile, highly efficient and metal-free transesterification under solvent-free condition
Gore, Kiran R.,Mittapelli, Lavanya L.
, (2020/10/27)
Transesterification is one of the important organic reactions employed in numerous industrial as well as laboratory applications for the synthesis of various esters. Herein, we report a rapid, highly efficient, and transition metal-free transesterification reaction in the presence of LiHMDS under solvent-free conditions. The transesterification reaction was carried out with three different benzoate esters and a wide range of primary and secondary alcohols (from C3-C18) in good to excellent yields (45 examples). By considering the commercial role of esters, this method will be promising for the facile synthesis of esters in industry-relevant applications.
