High-Fidelity,Narcissistic Self-Sorting in the Synthesis of Organometallic Assemblies from Poly-NHC Ligands

Highly selective, narcissistic self-sorting has been observed in the one-pot synthesis of three organometallic molecular cylinders of type [M₃{L-(NHC)₃}₂](PF₆)₃ (M=Ag⁺, Au⁺; L=1,3,5-benzene, triphenylamine, or 1,3,5-triphenylbenzene) from L-(NHC)₃ and silver(I) or gold(I) ions. The molecular cylinders contain only one type of tris-NHC ligand with no crossover products detectable. Transmetalation of the tris-NHC ligands from Ag⁺ to Au⁺ in a one-pot reaction with retention of the supramolecular structures is also demonstrated. High-fidelity self-sorting was also observed in the one-pot reaction of benzene-bridged tris-NHC and tetrakis-NHC ligands with Ag₂O. This study for the first time extends narcissistic self-sorting in metal–ligand interactions from Werner-type complexes to organometallic derivatives.     

K2CO3-Mediated,One-Pot,Multicomponent Synthesis of Medicinally Potent Pyridine and Chromeno[2,3-b]pyridine Scaffolds

An efficient one-pot, multicomponent synthesis of 3,5-dicyanopyridines has been developed from the reaction of malononitrile and different thiophenol or thiols with a variety of aldehydes (aromatic including hindered ones, heteroaromatic, and aliphatic) in the presence of 20 mol% of K₂CO₃ in refluxing 50% aqeuous ethanol. KMnO₄ has been utilized as a readily available, inexpensive oxidant for the in situ transformation of the initially formed dihydropyridine intermediate. K₂CO₃ also mediates the one-pot formation of chromeno[2,3-b]pyridines from reaction of salicylaldehyde or its analogs with malononitrile and thiol or thiophenols. Both of these conditions also work equally well under 50-fold scale-up conditions.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Cobalt-Catalyzed Aerobic Oxidative Cleavage of Alkyl Aldehydes: Synthesis of Ketones,Esters, Amides,and α-Ketoamides

A widely applicable approach was developed to synthesize ketones, esters, amides via the oxidative C−C bond cleavage of readily available alkyl aldehydes. Green and abundant molecular oxygen (O₂) was used as the oxidant, and base metals (cobalt and copper) were used as the catalysts. This strategy can be extended to the one-pot synthesis of ketones from primary alcohols and α-ketoamides from aldehydes.     

Ethanepolyphosphonates: Convenient One-Pot Syntheses of Esters,Acids, and Salts with High Yields and Their Properties

Abstract

Polyfunctional phosphonates CHP*₂–CHP*₂, CH₂P*–CHP*₂, CHR′P*–CHP*₂ (P* = P(O)(OR)₂; R = Me, Et, iPr, iOct; R′ = Ph, Mes, CH₂P*) were synthesized from chlorinated ethylenes by reaction with sodium dialkyl phosphites (RO)₂PONa in THF using convenient one-pot procedures. Some corresponding acids (R = H) of general type H_nL and salts were described. Molecular structures were deduced from NMR and X-Ray studies. Noncanonical rotamers in overcrowded molecules are discussed.     

Synthesis of stilbene analogues by one-pot oxidation-Wittig and oxidation-Wittig-Heck reaction

Synthesis of symmetrical (and unsymmetrical) stilbene derivatives is achieved by a combination of one-pot steps of Kornblum type oxidation of benzyl halide, its simultaneous in situ formation of phosphonium salt, and subsequently their Wittig reaction. In other variant it is oxidized to aldehyde, treated with ylide generated from phosphonium salt (CH₃PPh₃X) to give styrene, and subjected to Pd catalyzed Heck reaction with arylhalide to give stilbenes as the three-step one-pot sequence.     

A novel one-pot conversion of amines to homologated esters in poly(ethylene glycol)

The first deaminative homologation of amines (-CH₂NH₂) to esters (-CH₂CH₂COOEt) in one-pot is reported. The reaction proceeds through, formation of an aldehyde from an amine in the presence of Pd/C as catalyst followed by Wittig reaction and catalytic hydrogenation using poly(ethylene glycol) as the solvent in one-pot.     

One-Pot Reactions with Sol-Gel Entrapped Catalysts, Acids and Bases

Silica sol-gel entrapped acids, bases and organometallic catalysts are used successfully in one-pot reactions without interfering with each other. Both physically and covalently entrapped acids and bases were employed in these processes, including polystyrene sulfonic acid, 1-propane sulfonic acid, molybdosilicic acid (SiO₂-MoO₃), poly[(vinylbenzyltrimethyl)ammonium] hydroxide and 1,5,7-triazabicyclo[4.4.0]decene. The entrapped metal-based catalysts are Rh₂Co₂(CO)₁₂ and RuCl₂(PPh₃)₃. The one-pot reactions carried out with these heterogenized reagents and catalysts include formation of alkenes under acidic and basic conditions, C—C bond formation by condensation reactions with an -carbon to a carbonyl, hydroformylation and hydrogenation.     

Effect of lattice strain on structure,morphology, electrical conductivity and magneto-optical and catalytic properties of Ni-doped Mn3O4 nano-crystallites synthesized by microwave route

Ni-doped Mn₃O₄ nanoparticles (NPs) were synthesized by a simple one-pot microwave combustion procedure utilizing urea as a fuel. X-ray diffraction, transmission electron microscopy (TEM), diffuse reflectance spectroscopy, Photoluminescence spectra, and vibrating sample magnetometer. The particle size and the crystalline size measured from the HR-TEM monographs and XRD study suggest the similarity of the data collected from these two measurements. Photoluminescence (PL) spectra demonstrated increased luminescence amplitude with increased Ni concentration. Thus, the present study determines the time required for 4-nitrophenol yellow to colorless by Ni-doped Mn₃O₄ and Mn₃O₄ samples.     

One-pot synthesis of aza-Morita-Baylis-Hillman adducts from α-oxo ketene-S,S-acetals, arylaldehydes and nitriles

Promoted by TiCl₄, a series of α-(1,3-dithiolan-2-ylidene)-β-amino carbonyl derivatives--the aza-Morita-Baylis-Hillman adducts, have been synthesized from α-oxo cyclic ketene-S,S-acetals, arylaldehydes, and nitriles in good to excellent yields. A mechanism involving sequential Morita-Baylis-Hillman and Ritter reactions for this novel one-pot, three-component reaction is described.     

One-pot conversion of activated alcohols into 1,1-dibromoalkenes and terminal alkynes using tandem oxidation processes with manganese dioxide

Approaches to the preparation of C₁-homologated dibromoalkenes and terminal alkynes from activated alcohols using one-pot tandem oxidation processes (TOPs) with manganese dioxide are outlined. The conversion of alcohols into dibromoalkenes is described using dibromomethyltriphenylphosphonium bromide and the formation of terminal alkynes was achieved via a sequential one-pot, two-step process utilising the Bestmann-Ohira reagent.     

Metal-free one-pot oxidative conversion of benzylic alcohols and benzylic halides into aromatic amides with molecular iodine in aq ammonia, and hydrogen peroxide

Various primary alcohols, particularly benzylic alcohols, could be converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq. NH₃, followed by reaction with ∼30% aq H₂O₂. Similarly, various benzylic halides could be also converted into the corresponding aromatic amides in good yields in a one-pot manner by treatment with molecular iodine in aq NH₃, followed by reaction with ∼30% aq H₂O₂. The present reactions involve the metal-free one-pot oxidative conversion of benzylic alcohols and benzylic halides into the corresponding aromatic amides, respectively.     

An efficient and convenient synthesis of pentasubstituted pyrroles from alkyl acetoacetates,dialkyl acetylenedicarboxylates,and amines

A simple and efficient synthesis of pentasubstituted pyrroles has been developed using a one-pot, two-step reaction. The synthesis of a series of 4-hydroxypenta-1,3-diene-tricarboxylates from alkyl acetoacetates and dialkyl acetylenedicarboxylates in the presence of K₂CO₃, followed by cyclization with amines, gave the corresponding pyrroles in excellent yields.     

A Practical,One-Pot Preparation of Diisopinocampheylchloroborane

A one-pot preparation of the chiral reducing agent diisopinocampheylchloroborane (Ipc₂BCl) from α-pinene and borane methyl sulfide has been developed. The procedure obviates isolation of the air and moisture sensitive reagent, making it useful for large scale operations. Asymmetric reduction of ketones using the in situ prepared Ipc₂BCl is comparable to that using isolated reagent.     

Synthesis of 2,6-disubstituted dihydropyrans via an efficient BiBr3-initiated three component, one-pot cascade

The rapid synthesis of cis-2,6-disubstituted dihydropyrans is achieved in a three-component, one-pot cascade reaction. BiBr₃-mediated addition of ketene silyl acetals or silyl enol ethers to β,γ-unsaturated cis-4-trimethylsilyl-3-butenal provides a Mukaiyama aldol adduct containing a vinylsilane moiety tethered to a silyl ether. Addition of a second aldehyde initiates a domino sequence involving intermolecular addition followed by an intramolecular silyl-modified Sakurai (ISMS) reaction. Isolated yields of this one-pot reaction vary from 44 to 80% and all compounds were isolated as the cis-diastereomers (10 examples).     

Microwave-assisted,regioselective one-pot synthesis of quinolines and bis-quinolines catalyzed by Bi(III) immobilized on triazine dendrimer stabilized magnetic nanoparticles

Fe₃O₄-TDSN-Bi(III) was utilized as an efficient and reusable catalyst for the regioselective one-pot synthesis of quinoline derivatives from arylamines, arylaldehydes and methyl propiolate under microwave irradiation and solvent-free conditions. Also, bis-quinolines were obtained in high yields from dialdehydes or diamines. Atom-economy, high to excellent yields, easy work-up, as well as simple catalyst recovery and reusability are the key features of this procedure.     

Ruthenium Trichloride,Tricyclohexyl- phosphane, 1-Alkynes,Magnesium, Hydrogen,and Water—Ingredients of an Efficient One-Pot Synthesis of Ruthenium Catalysts for Olefin Metathesis

An active role is played by MgCl₂ during the conversion of the vinylidene precursor 2 into carbenes 3 (R=H, Ph; L=P(C₆H₁₁)₃). These complexes can be prepared in a convenient and very efficient one-pot synthesis and have a catalytic activity in metathesis comparable to that of Grubbs compound (Ph instead of CH₂R).     

A Practical,One-Pot Preparation of Diisopinocampheylchloroborane

A one-pot preparation of the chiral reducing agent diisopinocampheylchloroborane (Ipc₂BCl) from Δ-pinene and borane methyl sulfide has been developed. The procedure obviates isolation of the air and moisture sensitive reagent, making it useful for large scale operations. Asymmetric reduction of ketones using the in situ prepared Ipc₂BCl is comparable to that using isolated reagent.     

Formation of trialkyl quinoline-2,3,4-tricarboxylates by reaction of isatin, dialkyl acetylenedicarboxylates, and sodium O-alkyl carbonodithioates

An efficient one-pot synthesis of quinoline-2,3,4-tricarboxylates is described by reaction of isatin (indoline-2,3-dione) and electron-deficient acetylenic esters in the presence of sodium O-alkyl carbonodithioates, themselves prepared by addition of sodium hydride to a solution of an alcohol in CS₂.     

Pd2dba3/P(i-BuNCH2CH2)3N: a highly efficient catalyst for the one-pot synthesis of trans-4-N,N-diarylaminostilbenes and N,N-diarylaminostyrenes

A Pd₂dba₃/P(i-BuNCH₂CH₂)₃N catalyzed one-pot synthesis of unsymmetrically substituted trans-4-N,N-diarylaminostilbenes and both symmetrically and unsymmetrically substituted N,N-diarylaminostyrene derivatives is reported. The procedure involves two or more palladium catalyzed sequential coupling reactions (an amination and an inter-molecular Heck reaction) in one-pot using the same catalyst system with two different aryl halides, including aryl chlorides and hetero aryl halides as the coupling partners.     

A Keggin heteropoly acid as an efficient catalyst for an expeditious, one-pot synthesis of 1-methyl-2-(hetero)arylbenzimidazoles

The Keggin heteropoly acid, silicotungstic acid, H₄SiW₁₂O₄₀, has been demonstrated to be highly efficient for an expeditious, one-pot synthesis of 1-methyl-2-(hetero)arylbenzimidazoles from N-methyl-1,2-phenylenediamine and (hetero)aryl aldehydes in ethyl acetate at room temperature. The catalyst works equally well for N-phenyl-1,2-phenylenediamine.