ABSTRACT
Screening of the ICSN chemical library led to the discovery of 3-(4-chlorophenyl)-4-cyano-5-thioalkylthiophene 2-carboxylic acids as potent farnesyltransferase inhibitors. Enzymatic kinetic studies showed that this original FTI series belongs to the CaaX competitive inhibitor class. Preliminary SAR studies allowed us to improve the IC50 from 110 to 7.5 nM.
Subject(s)
Alkyl and Aryl Transferases/antagonists & inhibitors , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Thiophenes/chemistry , Thiophenes/pharmacology , Drug Discovery , Inhibitory Concentration 50 , Structure-Activity RelationshipABSTRACT
New tetraarylphosphonium (TAP)-supported alkyl- and arylcarbodiimides were synthesized and used as coupling reagents for esterification reactions, amidation reactions and dehydration reactions of hydroxyesters. Taking advantage of the solubility properties imparted by the tetraarylphosphonium unit, a simple precipitation and filtration allowed complete separation of the urea by-products. This paper describes the structure optimization study of the various TAP-supported carbodiimide reagents to obtain the desired reactivity and solubility profile. Furthermore, we have demonstrated that the diimide reagent can be regenerated from the urea to recycle the reagents.
Subject(s)
Amides/chemistry , Amides/chemical synthesis , Carbodiimides/chemistry , Esters/chemistry , Esters/chemical synthesis , Organophosphorus Compounds/chemistry , Esterification , Molecular Structure , Stereoisomerism , Water/chemistryABSTRACT
A stereoselective synthesis of coronafacic acid, a natural component of the phytotoxin coronatin, was achieved using an intramolecular Diels-Alder reaction as the key step. The triene precursor bearing a substituted diene and a vinylketone as dienophile was synthesized and then tested in the thermal intramolecular cyclization. We have devised a new strategy to assemble the E,Z-diene through the stereoselective aldol reaction of an ester enolate followed by a stereoselective dehydration. Following the thermal cyclization, the corresponding hydrindanone thereby obtained with the desired relative stereochemistry could easily be converted into the natural product. The synthesis of the coronafacic acid was accomplished in six steps in 29% overall yield.
