Substituent

About: Substituent is a research topic. Over the lifetime, 42877 publications have been published within this topic receiving 516716 citations. The topic is also known as: side chain & side group.

4-aminoquinazoline derivatives

Abstract: Disclosed are novel 4-aminoquinazoline derivatives of the formula (See formula I) (wherein Z is NR3R4 in which R3 is H and R4 is Q2 or phenyl substituted with (R5)q or Z is (See formula II) the dotted line represents an optional double bond; R5 is a substituent such as halo, amino, alkyl, alkoxy, etc.; R6 is a substituent such as hydroxyl, amino, sulfo, alkoxy, carboxyl, etc.; q is 0-3; o is 0-2; Q2 is a 9- or 10-membered bicyclic heterocyclic moiety; Q1 is Ar-Y-X in which Ar is mono- or bicyclic (hetero)aryl, X is alkenylene, alkynylene or bond and Y is (CH2)p where p is 0-5; R1 is a substituent such as trifluoromethyl; n is 0-3; m is 1-2) and their pharmaceutically acceptable salts. Those compounds and the salts are useful for the treatment of hyperproliferative disorders and conditions in mammals.

Catalytic Asymmetric Intermolecular Stetter Reaction of Heterocyclic Aldehydes with Nitroalkenes: Backbone Fluorination Improves Selectivity

Abstract: The catalytic asymmetric intermolecular Stetter reaction of heterocyclic aldehydes and nitroalkenes has been developed. We have identified a strong stereoelectronic effect on catalyst structure when a fluorine substituent is placed in the backbone. X-ray structure analysis provides evidence that hyperconjugative effects are responsible for a change in conformation in the azolium precatalyst. This new N-heterocyclic carbene precursor bearing fluorine substitution in the backbone results in significantly improved enantioselectivities across a range of substrates.