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An efficient one-pot multistep strategy has been developed, comprising auto-oxidative difunctionalization of alkenes, oxidation of sulfides, and a further reduction of peroxides for the synthesis of complex β-hydroxysulfone derivatives from phenthiols and alkenes. This method has several advantageous characteristics, including readily available substrates, low-cost and environmental benign reagents, nontoxic and renewable solvents, and mild reaction conditions. The application of this transformation to the multigram-scale preparation of the anticancer drug bicalutamide is accomplished.

A bioinspired synthesis of the sedaxane metabolite 2 from intermediate 3 using catalytic VO(acac)2 and O2 is described. Intermediate 3 was synthesized starting from 2-bromostyrene in four steps. The inner cyclopropyl ring of 3 was assembled with trans geometry using a highly diastereoselective Nishiyama cyclopropanation, and the outer hydroxycyclopropyl ring was installed using the Kulinkovich cyclopropanation. Additionally, conversion of 3 into 2 was demonstrated in in vitro microbial culture experiments consisting of bacteria and fungi.

A metal-free method for fast and clean anilide formation from perfluoroaryl azide and thioacid is presented. The reaction proved highly efficient, displaying fast kinetics, high yield, and good chemoselectivity. The transformation was compatible with various solvents and tolerant to a wide variety of functional groups, and it showed high performance in polar protic/aprotic media, including aqueous buffer systems.

An organocatalytic protocol for the syntheses of 2-substituted benzoxazoles and benzothiazoles is described from alkyl-/arylanilides and alkyl-/arylthioanilides using 1-iodo-4-nitrobenzene as catalyst and oxone as an inexpensive and environmentally safe terminal oxidant at room temperature in air via oxidative C-H functionalization and C-O/S bond formation. The procedure is simple and general and provides an effective route for the construction of functionalized 2-alkyl-/arylbenzoxazoles and 2-alkyl-/arylbenzothiazoles with moderate to high yields. The synthetic and mechanistic aspects have been described.

An improved methodology for the preparation of enantiopure oxabicyclo[3.2.1]octadienes via a stereodivergent resolution is reported. High catalyst control proximal to the oxabridged stereocenter produces readily separable diastereomers in high yield (>92%) and with excellent optical purity (>95% ee). This resolution strategy is amenable to large-scale preparations, and the utility of the resolution was further demonstrated in the asymmetric preparation of a key intermediate used in the synthesis of the antibiotic (-)-platensimycin.

A mild and efficient dual-mode Lewis acid induced Diels-Alder (DA)/carbocyclization cascade cyclization reaction has been developed for construction of the tricyclic core of ent-kaurenoids in one pot with the aid of a theoretical study on the π,σ-Lewis acidities of a variety of Lewis acids. With ZnBr2 as the dual-mode Lewis acid, a series of substituted enones and dienes underwent DA/carbocyclization cascade cyclization reaction smoothly at room temperature and provided the tricyclic cyclized products in one pot with good yields and high diastereoselectivity. The tricyclic cyclized product has been successfully utilized as a common intermediate for formal syntheses of (±)-platensimycin and (±)-platencin.

A practical one-pot and regiospecific three-component process for the synthesis of 2,3-disubstituted indoles from 2-bromoanilides was developed via consecutive palladium-catalyzed Sonogashira coupling, amidopalladation, and reductive elimination.

A highly stereoselective synthesis of the racemic oxatetracyclic core of platensimycin has been accomplished from a known bicyclic epoxy lactone by an 11-step sequence that involves a Diels-Alder cyclcoaddition to construct its cis-decalenone structural motif with complete regio- and stereoselectivity and a ring-closing metathesis to establish its whole carbon framework.

A metal-free method for the direct regioselective fluorination of anilides has been developed. In the presence of bis(tert-butylcarbonyloxy)iodobenzene (PhI(OPiv)(2)) and hydrogen fluoride-pyridine, the para-fluorination products of anilides were obtained in moderate to good yields. Because of its operational safety and the use of readily available reagents, this new procedure provides facile access to a variety of para-fluorinated anilides.

A palladium-catalyzed ortho-alkoxylation of anilides with both primary and secondary alcohols via ligand-directed C-H activation has been explored. This alkoxylation promoted by catalytic methanesulfonic acid proceeds well at room temperature in most cases and affords aryl alkyl ethers in moderate to good yields.

An oxidative Prins-pinacol tandem process mediated by a hypervalent iodine reagent has been developed. This oxidative version of the famous tandem process fits within the concept of "aromatic ring umpolung" and allows the stereoselective transformation of simple phenols into highly elaborated spirocyclic dienone cores containing several quaternary carbon centers. The scope and the limitations of this process, including the study of its stereoselectivity, are described in this article. As a direct application of this stereoselective process, we describe the formal synthesis of (-)-platensimycin, an important antibiotic agent.

A new approach for the convenient synthesis of dibenzazepinones is reported. The key step is the formation of the seven-membered ring through palladium-catalyzed intramolecular arylation of an anilide enolate. The reactions were completed in 10 min at 100 °C with moderate to excellent yields. Aminodibenzazepinone 1, the core structure in the γ-secretase inhibitor LY411575, can be prepared in five steps from 2-bromophenylboronic acid and 2-iodoaniline in 60% overall yield. The synthesis reported here compares favorably with presently available approaches to this interesting ring system.

A novel and selective palladium-catalyzed C-H activation protocol has been developed for the synthesis of 3-aryl quinolin-2(1H)-ones and 3-(1-arylmethylene)oxindoles with use of PivOH as the switch. In the presence of Pd(OAc)(2), AgOAc, and PivOH, a variety of N-methyl anilides reacted with arenes to afford the corresponding 3-aryl quinolin-2(1H)-ones in moderate yields, whereas the selectivity was shifted toward 3-(1-arylmethylene)oxindoles in the absence of PivOH.

A mild and cost-efficient chemo-enzymatic method for the synthesis of C-terminal arylamides of amino acid and peptides is described. Using the industrial serine protease Alcalase under near-anhydrous conditions, C-terminal arylamides of N-Cbz-protected amino acids and peptides could be obtained from the corresponding C-terminal carboxylic acids, methyl (Me) or benzyl (Bn) esters, in high chemical and enantio- and diastereomeric purities. Yields ranged between 50% and 95% depending on the size of the aryl substituents and the presence of electron-withdrawing substituents. Complete alpha-C-terminal selectivity could be obtained even in the presence of various unprotected side-chain functionalities such as beta/gamma-carboxyl, hydroxyl, and guanidino groups. In addition, the use of the cysteine protease papain and the lipase Cal-B gave anilides in high yields. The chemo-enzymatic synthesis of arylamides proved to be completely free of racemization, in contrast to the state-of-the-art chemical methods.

A series of biologically intriguing pyroglutamic acids were synthesized in racemic form by employing indole-isonitrile and ammonium acetate in the Ugi 4-center-3-component reaction of gamma-ketoacids.

The Heck coupling of acrylanilides with 4-bromo-2-chloro-3-iodo-pyridine using palladium acetate can produce bis-Heck products or undergo an unusual tandem Heck-lactamization ring formation to generate 5-chloro-1-aryl-1,6-naphthyridin-2(1H)-ones.

A new, mild, and efficient method has been developed for the synthesis of 2-substituted benzothiazoles via the intramolecular cyclization of thioformanilides by using hypervalent iodine reagents in CH2Cl2 at ambient temperature. The reaction proceeds via a thiyl radical in high yields to give the novel compound oxybis benzothiazole and is also amenable to generating combinatorial libraries of heterocyclic compounds by solid-phase synthesis.

Aliphatic amines are sensitively and discriminatively detected through binding with demethylated naphthol AS-BI (7-bromo-3-hydroxy-2-naphth-o-hydroxyanilide, 2) and fluorescence of the resulting complex. Recognition of the amine by the chemosensor 2 occurs via proton transfer of the naphtholic proton to the amine and is facilitated by the presence of the phenol group. Amine basicity is the primary controller of detection. Poorly basic aromatic and conjugated amines such as pyridine and aniline are not detected. Hydrogen bonding within the complex allows further differentiation of aliphatic amines. Doubly primary, conformationally flexible diamines are the most sensitive to detection, followed by secondary amines.

A general method for the formation of benzoxazoles via a copper-catalyzed cyclization of ortho-haloanilides is reported. This approach complements the more commonly used strategies for benzoxazole formation which require 2-aminophenols as substrates. The reaction involves an intramolecular C-O cross-coupling of the ortho-haloanilides and is believed to proceed via an oxidative insertion/reductive elimination pathway through a Cu(I)/Cu(III) manifold. The reaction is also applicable to the formation of benzothiazoles. A variety of ligands including 1,10-phenanthroline and N,N'-dimethylethylenediamine were shown to provide ligand acceleration/stabilization in the reaction. Optimal conditions for cyclization used a catalyst combination of CuI and 1,10-phenanthroline (10 mol %). The method was amenable to a parallel-synthesis approach, as demonstrated by the synthesis of a library of benzoxazoles and benzothiazoles substituted at various positions in the ring. Most examples utilized the cyclization of ortho-bromoanilides, but ortho-iodoanilides and ortho-chloroanilides also undergo a reaction under these conditions. The rate of reaction of the ortho-haloanilides follows the order I > Br > Cl, consistent with oxidative addition being the rate-determining step.

[reaction: see text] N-Aryl-5,5-diphenyl-4-pentenamidyl radicals (3) were produced by 266 nm laser-flash photolysis of the corresponding N-(phenylthio) derivatives, and the rate constants for the cyclizations of these radicals were measured directly. The 5-exo cyclization reactions were fast (k(c) > 2 x 10(5) s(-1)), and radicals 3 generally behaved as electrophilic reactants with a Hammett correlation of rho = 1.9 for five of the six radicals studied. However, the p-methoxyphenyl-substituted radical 3f cyclized much faster than expected from the Hammett analysis. Variable temperature studies of parent radical 3a (aryl = phenyl) gave an Arrhenius function with log k = 9.2 - 4.4/2.3RT (kcal/mol). The rate constant for the reaction of p-ethylphenyl-substituted anilidyl radical 3b with Bu(3)SnH at 65 degrees C was k(T) = 4 x 10(5) M(-1) s(-1).

[structures: see text] Syntheses and structural analyses of bivalent carbohydrates based on anilides of glucuronic acid are described. Secondary anilides predominantly adopted the Z-anti structure; there is also evidence for population of the Z-syn isomer. Bivalent tertiary anilides displayed two signal sets in their NMR spectra, consistent with the presence of (i) a major isomer where both amides have E configurations (EE) and (ii) a minor isomer where one amide is E and the other Z (EZ). Qualitative NOE/ROE spectroscopic studies in solution support the proposal that the anti conformation is preferred for E amides. The crystal structure of one bivalent tertiary anilide showed E-anti and E-syn structural isomers; intramolecular carbohydrate-carbohydrate stacking was observed and mediated by carbonyl-pyranose, azide-azide, and pyranose-aromatic interactions. The EE to EZ isomer ratio, or the degree of folding, for tertiary amides, was greatest for a bivalent compound containing two alpha-glycosyl azide groups; this was enhanced in water, suggesting that hydrophobic interactions are partially but not wholly responsible. Computational methods predicted azide-aromatic (N...H-C interaction) and azide-azide interactions for folded isomers. The close contact of the azide and aromatic protons (N...H-C interaction) was observed upon examination of the close packing in the crystal structure of a related monomer. It is proposed that the alpha-azide group is more optimally aligned, compared to the beta-azide, to facilitate interaction and minimize the surface area of the hydrophobic groups exposed to water, and this leads to the increased folding. The alkylation of bivalent secondary anilides induces a switch from Z to E amide that alters the scaffold orientation. The synthesis of a bivalent mannoside, based on a secondary anilide scaffold, for investigation of mannose-binding receptor cross-linking and lattice formation is described.

[structures: see text] The synthesis of anilides derived from glucuronic acid is described. Secondary anilides had a Z configuration in the solid state and showed intramolecular and intermolecular hydrogen bonding. However, on the basis of NMR and IR studies, there was generally no evidence for the same hydrogen bonding in solution. Tertiary anilides showed a strong preference for the E configuration on the basis of NOE studies and molecular mechanics calculations. The alkylation of the secondary anilides induces a configurational switch that alters the orientation of the aromatic group with respect to the pyranose, which has relevance for presentation or orientation of pharmacophoric groups on carbohydrate scaffolds.

The anticancer drug (R,S)-biscaltamide was prepared in three steps in >90% overall yield. A key step in the new synthesis involved a new nucleophilic aromatic substitution reaction of methacrylamide anion.

Catalysts comprised Pd(OAc)(2) and either PCy(3) or sterically hindered N-heterocyclic carbene ligands provide fast rates for a palladium-catalyzed synthesis of oxindoles by amide alpha-arylation. This catalyst system allowed for room-temperature reactions in some cases and reactions of aryl chlorides at 70 degrees C. Most important, reactions occurred in high yields under mild conditions to form the quaternary carbon in alpha,alpha-disubstituted oxindoles. The combined inter- and intramolecular reaction afforded an efficient synthetic method for formation of alpha-aryloxindole derivatives. Surprisingly, catalysts containing tert-butylphosphine ligands, which have been most reactive for ketone arylations, were less active than those containing PCy(3). Use of new, optically active heterocyclic carbene ligands gave substantial enantioselectivity in formation of an alpha,alpha-disubstituted oxindole. In contrast, a variety of optically active phosphine ligands that were tested gave poor enantioselectivity. Mechanistic studies showed that the reaction involves rate-limiting oxidative addition of aryl halide. Base-induced formation of and reductive elimination from an arylpalladium enolate intermediate were both faster than oxidative addition. Deprotonation of the tethered amide appeared to be faster than reductive elimination of the resulting palladium enolate to form the oxindole product.