114604-96-5

We report the method for synthesis of indole- and pyrrole-fused seven-membered nitrogen heterocycles by means of acid-base switchable cyclization reactions. The reactions involved cleavage of amide C?N bonds, chemoselective N-1 or C-3 acylation, and 1,4-M

1,5-Disubstituted indole-2-carboxaldehyde derivatives 1a–h and glycine alkyl esters 2a–c are shown to undergo a novel cascade imination-heterocylization in the presence of the organic base DIPEA to provide 1-indolyl-3,5,8-substituted γ-carbolines 3aa–ea in good yields. The γ-carbolines are fluorescent and exhibit anticancer activities against cervical, lung, breast, skin, and kidney cancer cells.

The disclosure relates to compounds that act as allosteric inhibitors of epidermal growth factor receptor (EGFR); pharmaceutical compositions comprising the compounds; and methods of treating or preventing kinase-mediated disorders, including cancer and other proliferation diseases.

We report a one-step catalytic, enantioselective method for the preparation of homoallylic N-Boc amines directly from acetals. Reactive iminium ion intermediates are generated in situ through the combination of an acetal, a chiral thiourea catalyst, trialkylsilyl triflate, and N-Boc carbamate and are subsequently trapped by a variety of allylsilane nucleophiles. No homoallylic ether byproducts are detected, consistent with allylation of the iminium intermediate being highly favored over allylation of the intermediate oxocarbenium ion. Acetals derived from aromatic aldehydes possessing a variety of functional groups and substitution patterns yield homoallylic amines with excellent levels of enantiomeric enrichment. Experimental and computational data are consistent with an anchoring hydrogen-bond interaction between the protioiminium ion and the amide of the catalyst in the enantiodetermining transition state, and with stereodifferentiation achieved through specific noncovalent interactions (NCIs) with the catalyst pyrenyl moiety. Evidence is provided that the key NCI in the major pathway is a π-stacking interaction, contrasting with the cation-πinteractions invoked in previously studied reactions promoted by the same family of aryl-pyrrolidino-H-bond-donor catalysts.

An efficient, unified approach for the synthesis of β-carbolines, γ-carbolines, and other fused azaheteroaromatics has been realized under metal-free conditions, from propargylic amines and (hetero)aromatic aldehydes. This unified strategy provides β- and

A concise method for the synthesis of 1,2-fused tricyclic indole scaffolds by domino cyclization involving a Pd-catalyzed Sonogashira coupling, indole cyclization, regio- and chemoselective N-1 acylation, and 1,4-Michael addition is reported. This method

The study toward the total synthesis of (R)-(+)-harmicine is reported in this paper. The enantioselective synthesis of pyrrolidinone, the main backbone of of (R)-(+)-harmicine, has been completed by the methodology based on photo-induced Wolff rearrangement of α-diazo-β-carbonyl compounds. Copyright

A new photoinduced electron-transfer-promoted redox fragmentation of N-alkoxyphthalimides has been developed. Mechanistic experiments have established that this reaction proceeds through a unique concerted intramolecular fragmentation process. This distinctive mechanism imparts many synthetic advantages, which are highlighted in the redox fragmentation of various heterocyclic substrates.

A synthetic method for azaheterocycles from aryl ketone O-acetyl oximes and internal alkynes has been developed by using the Cu(OAc)2- [Cp*RhCl2]2 bimetallic catalytic system. The reactions proceeded with both of anti- and syn-isomers of oximes with a wide scope of substituents. The Cu-Rh bimetallic system could be applied for the synthesis of isoquinolines as well as β-carboline, furo[2.3-c]pyridine, pyrrolo[2,3-c]pyridine, and thieno[2,3-c]pyridine derivatives.

Starting from l/H-indole-2-carboxylic acid, a series of spiro[2oxoindole-pyrrolidines] could be synthesized in a straightforward manner. The key reaction is a Kharasch radical cyclization reaction of trichloroacetylated precursors. The identity of the tricyclic final products that were formed could be de-termined as spiro[2-oxoindole-pyrrolidines] by using a combination of different analytical techniques (1H NMR, 13C NMR, gHMBC, HRMS) and additional reactions. The produced skeletons are interesting from a medicinal point of view.

DABCO-mediated Morita-Baylis-Hillman reactions of several 1-substituted-indole-2-carboxaldehydes are disclosed. It was discovered that carboethoxy or tert-butoxycarbonyl groups installed at N-1 undergo cleavage under the reaction conditions to afford 2-su

Dirhodium(II)-catalyzed reaction of 3-indolyl α-diazo-β- ketoester 25 in the presence of hexanamide results in competing metal carbene N-H insertion and Wolff rearrangement. The corresponding phenyl diazoketoester 32, on the other hand, gives only the product of N-H insertion, suggesting that the indole moiety is more prone to 1,2-rearrangement. The competing processes were investigated in a range of 3-indolyl α-diazo-β-ketoesters (36, 38, 40, 44); these studies established that the Wolff rearrangement could be effectively suppressed by the presence of a strong electron-withdrawing group on the indole nitrogen. Dirhodium(II) catalysts were also more effective than copper or Lewis acid catalysts in favoring the insertion process. The products of N-H insertion, the ketoamides (26, 47, 49, 51, 53), were readily cyclodehydrated to the corresponding 5-(3-indolyl)-oxazoles. The N-H insertion/cyclodehydration methodology was used in a formal synthesis of the marine natural product martefragin A. Thus the N-Boc homoisoleucine amide 23, prepared by asymmetric hydrogenation of a dehydro amino acid, underwent N-H insertion with the rhodium carbene derived from the N-nosyl indolyl diazoester 40, followed by cyclodehydration and deprotection to give the 5-(3-indolyl)oxazole martefragin A precursor 75.

Tryptophan 1 (Trp) is superior to all other naturally occurring peptide residues in its ability to bind cations (the cation - π interaction). In an effort to expand the toolbox of Trp-like amino acids, in this note we report catalytic asymmetric syntheses of Trp regioisomers 2a - e, where the alanine unit is attached not to C-3 of indole but to C-2, C-4, C-5, C-6, or C-7. Excellent asymmetric induction is obtained in each case (generally >97% ee). Ab initio calculations suggest that the indole nuclei of 2a-e will bind Na+ with the same affinity as that of Trp.