A Mild and Regioselective Route to Functionalized Quinazolines
作者:Tracy M. M. Maiden、Stephen Swanson、Panayiotis A. Procopiou、Joseph P. A. Harrity
DOI:10.1002/chem.201502891
日期:2015.10.5
A Rh‐catalyzed ortho‐amidation cyclocondensation sequence gave a range of 4‐aminoquinazolines in high yield. The method features a remarkably mild C(sp2)H activation step and can be exploited to rapidly access compounds with established biological activity.
Snipping tool: Zn(OTf)2 is an efficient catalyst for selective cleavage of amides bearing a β‐hydroxyethyl group on the nitrogen atom. The mechanism involves an N,O‐acyl rearrangement and transesterification. This new catalytic system can be applied to sequence‐specific peptide bond scission at the amine side of a serine residue. Tf=trifluoromethanesulfonyl.
N-Heterocyclic Carbene-Catalyzed Amidation of Unactivated Esters with Amino Alcohols
作者:Mohammad Movassaghi、Michael A. Schmidt
DOI:10.1021/ol050773y
日期:2005.6.1
[reaction: see text] A catalytic amidation of unactivated esters with aminoalcohols is described. A series of solution studies in addition to the first X-ray structure of a carbene-alcohol complex support a carbene-base nucleophile activation mechanism.
Polymer-mounted N3P(MeNCH2CH2)3N: a green, efficient and recyclable catalyst for room-temperature transesterifications and amidations of unactivated esters
作者:Venkat Reddy Chintareddy、Hung-An Ho、Aaron D. Sadow、John G. Verkade
DOI:10.1016/j.tetlet.2011.09.102
日期:2011.12
Merrifield resin-supported N3P(MeNCH2CH2)3N shows excellent activity in the transesterification of higher esters such as glyceryl tribenzoate to methyl esters. The catalyst was successfully cycled 20 times (albeit with an increase in reaction time) without compromising yield up to the 20th cycle. The catalyst also showed good performance in amidation reactions of unactivated esters with amino alcohols