62157-90-8Relevant academic research and scientific papers
Efficient Transfer of Chelating Amides into Different Types of Esters and Lactones
Jakob, Uwe,Mundinger, Stephan,Bannwarth, Willi
, p. 6963 - 6974 (2016/02/18)
We describe a general and versatile approach for the conversion of carboxylic acid amides into their corresponding esters despite the fact that the former are thermodynamically more stable. The transformations are mediated by the coordination of CuI by a chelating entity. The resulting weakening of the amide bond allows for nucleophilic attack by alcoholic hydroxyl functions. The principle is demonstrated for a wide variety of transformations, leading to different kinds of esters and lactones. Due to their high resonance energy, amides are generally very stable towards solvolysis. However, bispicolylamides can be activated for alcoholysis by an unusual metal coordination involving the electron pair of the amide nitrogen. Herein, we widened the scope of the reaction by transforming the amides into a range of esters and lactones.
Stereochemical Studies on Hemiorthothiol and Hemiorthothiolate Tetrahedral Intermediates
Khouri, Farid F.,Kaloustian, Moses K.
, p. 6683 - 6695 (2007/10/02)
This study deals with hemiorthothiol-RC(OR')2SH-tetrahedral intermediates including (a) two acyclic ones of type , (b) two types of monocyclics and , and (c) four bicyclic systems , , , and .The breakdown of (R = Ph, R' = Et) led to thiono esters 34 and 35; that of (R = Me, Ph) resulted in hydroxy thiono esters 36-39, whereas the cleavage of (R =Me, Et) yielded thionolactones 49-53 and hydroxy thiono esters 55-58.The study of rigid bicyclic intermediates - helped uncover the role of stereoelectronic effects in the breakdown of hemiorthothiol tetrahedral intermediates.Finally, a family of isolable hemiorthothiolate tetrahedral intermediates-RC(OR')2S-+Na-viz. ->--> (monocyclic) and -> (bicyclic) is reported.
