ABSTRACT
A general and efficient NH insertion reaction of rhodium pyridyl carbenes derived from pyridotriazoles was developed. Various NH-containing compounds, including amides, anilines, enamines, and aliphatic amines, smoothly underwent the NH insertion reaction to afford 2-picolylamine derivatives. The developed transformation was further utilized in a facile one-pot synthesis of imidazo[1,5-a]pyridines.
Subject(s)
Carbolines/chemistry , Organometallic Compounds/chemistry , Picolines/chemical synthesis , Pyridines/chemistry , Rhodium/chemistry , Triazoles/chemistry , Catalysis , Molecular Structure , Picolines/chemistry , Pyridines/chemical synthesisABSTRACT
A novel mode of reactivity for the diazo group, the 1,3-addition of a nucleophile and an electrophile to the diazo group, has been realized in the intramolecular aminoalkylation of ß-amino-α-diazoesters to form tetrasubstituted 1,2,3-triazolines. The reaction exhibited a broad scope, good functional group tolerance, and excellent diastereoselectivity. In addition, a new Au-catalyzed intramolecular transannulation reaction of the obtained propargyl triazolines to give pyrroles has been discovered.
Subject(s)
Pyrroles/chemistry , Quinolones/chemical synthesis , Triazoles/chemical synthesis , Alkylation , Amines/chemistry , Mass Spectrometry , Quinolones/chemistry , Stereoisomerism , Triazoles/chemistryABSTRACT
The ubiquitous nature of C-H bonds in organic molecules makes them attractive as a target for rapid complexity generation, but brings with it the problem of achieving selective reactions. In developing new methodologies for C-H functionalization, alkenes are an attractive starting material because of their abundance and low cost. Here we describe the conversion of 1-alkenes into 1,4-diols. The method involves the installation of a new Si,N-type chelating auxiliary group on the alkene followed by iridium-catalysed C-H silylation of an unactivated δ-C(sp(3))-H bond to produce a silolane intermediate. Oxidation of the C-Si bonds affords a 1,4-diol. The method is demonstrated to have broad scope and good functional group compatibility by application to the selective 1,4-oxygenation of several natural products and derivatives.
Subject(s)
Alcohols/chemistry , Alkenes/chemistry , Biological Products/chemical synthesis , Biological Products/chemistry , Carbon/chemistry , Catalysis , Hydrogen/chemistry , Iridium/chemistry , Oxidation-Reduction , Quantum Theory , Silanes/chemistryABSTRACT
A novel three-component coupling (3-CC) reaction of 2-aminoazines, aromatic aldehydes, and diazo-compounds producing polyfunctional ß-amino-α-diazo-compounds has been developed. The reaction features an unprecedented heterocycle-assisted addition of a diazo-compound to an imine. The obtained diazoesters were efficiently converted into valuable heterocycles as well as ß-amino acid derivatives.
Subject(s)
Aldehydes/chemistry , Amino Acids/chemical synthesis , Azo Compounds/chemistry , Imines/chemistry , Pyridines/chemistry , Amino Acids/chemistry , Azo Compounds/chemical synthesis , Catalysis , Combinatorial Chemistry Techniques , Esters , Molecular Structure , Pyrimidinones/chemical synthesis , Pyrimidinones/chemistrySubject(s)
Chemistry Techniques, Synthetic/methods , Heterocyclic Compounds, 1-Ring/chemical synthesis , Heterocyclic Compounds, 2-Ring/chemical synthesis , Transition Elements/chemistry , Heterocyclic Compounds, 1-Ring/chemistry , Heterocyclic Compounds, 2-Ring/chemistry , Transition Elements/chemical synthesisABSTRACT
The efficient Pd-catalyzed double-fold C-H oxygenation of arenes into resorcinols using the newly developed 2-pyrimidyldiisopropylsilyl (PyrDipSi) directing group is described. Its use allows for the sequential introduction of OAc and OPiv groups in a one-pot manner to produce orthogonally protected resorcinol derivatives. The PyrDipSi group is superior to the previously developed 2-pyridyldiisopropylsilyl (PyDipSi) group, as it is efficient for monooxygenation of ortho-substituted arenes. Notably, the PyrDipSi group can be easily installed into arene molecules and can be easily removed or modified after the oxygenation reaction.
Subject(s)
Hydrocarbons, Aromatic/chemistry , Oxygen/chemistry , Palladium/chemistry , Resorcinols/chemistry , Silicon Compounds/chemistry , CatalysisABSTRACT
The synthesis of new, artificial ribonucleases containing two amino acid residues connected by an aliphatic linker has been developed. Target molecules were synthesized via a catalytic three-component Ugi reaction from aliphatic diisocyanides. Preliminary investigations proved unspecific nuclease activity of the new compounds towards single-stranded RNA and double-stranded circular DNA.
Subject(s)
Acetates/chemistry , Acetates/chemical synthesis , Acylation , Aldehydes/chemistry , Alkylation , Biological Products/chemical synthesis , Biological Products/chemistry , Heterocyclic Compounds/chemistry , Imines/chemistry , Ketones/chemistry , Polymerization , Stereoisomerism , Sulfur/chemistryABSTRACT
The first example of a diastereoselective thio-Ugi reaction with chiral alpha-methylbenzylamine is described. The reaction results in formation of two diastereomers of thioamides, the major of which was isolated. We have found that under similar conditions stereochemical results of the thio-Ugi reaction are opposite to stereochemical results of the Ugi reaction. Several chiral thioamides were synthesized. The reaction of thioamides with ammonia results in substituted amidines, which can be cyclized to imidazole derivatives in aqueous HCl. The synthesis of chiral imidazole derivatives was elaborated. Using certain approaches, both isomers of a key synthon in the synthesis of SB203386 (an orally bioactive HIV-1 protease inhibitor) were prepared. The scope, limitations, and stereochemistry of the approach are discussed.
