Guest Binding Drives Reversible Atropisomerism in Cavitand Hosts
作者:Thanh V. Nguyen、David J. Sinclair、Anthony C. Willis、Michael S. Sherburn
DOI:10.1002/chem.200900695
日期:2009.6.8
Guest‐love‐ometer: The equilibrium inside–outside atropisomeric ratio of ortho‐substituted phenyl cavitands shows a strong solvent dependence. The competition between the ortho‐substituent and the solvent guest for the bowl cavity leads to a sensitive system for the measurement of relative guestbinding affinities.
Efficient microwave synthesis of novel aromatic esters catalyzed by zirconia and its modified forms: a kinetic study
作者:N. Thimmaraju、S. Z. Mohamed Shamshuddin、S. R. Pratap、K. Raja
DOI:10.1039/c5ra20430e
日期:——
solid acids was evaluated in the synthesis of novel aromatic esters by the assistance of microwave irradiation and the catalytic activity of these solid acids was compared with pTsOH. The results clearly indicated that the zirconia based solid acids are efficient green catalysts for esterification reactions, which gave a maximum yield of the ester in a shorter reaction time and comparable catalytic activity
We disclose the microwave-assisted remote-C–H functionalization aided by a simple nitrile directing template via enabling the meta-C–H arylation, acetoxylation, and cyanation with broad substrate compatibility including drug diversifications.
New chiral hypervalent iodine(V) compounds as stoichiometric oxidants
作者:Sabine M. Altermann、Sascha Schäfer、Thomas Wirth
DOI:10.1016/j.tet.2010.05.079
日期:2010.7
The synthesis and application of some new hypervalent iodine compounds bearing chiral and achiral ester motives derived from easily accessible starting materials is presented. The oxidation is carried out using dimethyldioxirane as an oxidant providing the desired compounds in moderate to high yields. A crystal structure analysis for one iodine(V) derivative is investigated. The λ5-iodanes are applied
An efficient and selective method for metal- and oxidant-free deaminated esterification of tertiary amines is presented. In this protocol, ynoates play a key role to activate the Csp3−N bond through a process of in situ generation of zwitterionic salts. The transformations show that Csp3−N bond in the zwitterionic species has a lower dissociation energy than Csp2−N bond, leading to break preferentially