109811-96-3

Upstream product

• 603-76-9 1-methylindole 
• 5153-67-3 nitrostyrene 
• 158953-96-9 1-methyl-3-deuterio-1H-indole 
• 100-42-5 styrene 
• 102-96-5 (2-nitroethenyl)benzene 

Downstream Products

• 102889-07-6 2-(1-methyl-1H-indol-3-yl)-2-phenylethan-1-amine 

Relevant academic research and scientific papers

Structural considerations for charge-enhanced Br?nsted acid catalysts

All three N-methylated and N-protonated hydroxypyridinium BArF4– salt isomers were synthesized and their hydrogen bond donating abilities were investigated. DFT and G4 theory computations along with IR spectroscopic measurements were found to be effective methods for predicting the catalytic activities of these O–H and N–H Br?nsted acids. A UV-vis titration approach for rapidly quantifying hydrogen bond donating ability revealed that carbon-hydrogen bonds also can participate in electrostatic interactions, but the presence of multiple equilibrium complexes results in a limitation of this method. In the methylated series of hydroxypyridines, the ortho and para isomers displayed modest rate enhancements relative to the meta derivative. Protonation introduces a new acidic site and the ortho hydroxypyridinium ion salt is a significantly more active catalyst than all of the other species examined. This is indicative of bidentate activation by the N–H and O–H acidic sites, and suggests a new design strategy for improving charge-enhanced catalysts.

Preorganized Hydrogen Bond Donor Catalysts: Acidities and Reactivities

Measured DMSO pKa values for a series of rigid tricyclic adamantane-like triols containing 0-3 trifluoromethyl groups (i.e., 3(0)-3(3)) are reported. The three compounds with CF3 substituents are similar or more acidic than acetic ac

Cooperative hydrogen-bonding effects in silanediol catalysis

The importance of cooperative hydrogen-bonding effects and SiOH-acidification is described for silanediol catalysis. NMR binding, X-ray, and computational studies provide support for a unique dimer resulting from silanediol self-recognition. The significa

Metal-templated hydrogen bond donors as "organocatalysts" for carbon-carbon bond forming reactions: Syntheses, structures, and reactivities of 2-guanidinobenzimidazole cyclopentadienyl ruthenium complexes

The reaction of 2-guanidinobenzimidazole (GBI) and (η5-C5H5)Ru(PPh3)2(Cl) in refluxing toluene gives the chelate [(η5-C5H5)Ru(PPh3)(GBI)]+Cl- (1+Cl-; 96%). Subsequent anion metatheses yield the BF4-, PF6-, and BArf- (B(3,5-C6H3(CF3)2)4-) salts (77-85%). Reactions with CO give the carbonyl complexes [(η5-C5H5)Ru(CO)(GBI)]+X- (2+X-; X- = Cl-, BF4-, PF6-, BArf-; 87-92%). The last three salts can also be obtained by anion metatheses of 2+Cl- (77-87%), as can one with the chiral enantiopure anion P(o-C6Cl4O2)3- ((δ)-TRISPHAT-; 81%). The reaction of [(η5-C5H5)Ru(CO)(NCCH3)2]+PF6- and GBI also gives 2+PF6- (81%). The pentamethylcyclopentadienyl analogues [(η5-C5Me5)Ru(CO)(GBI)]+X- (3+X-; X- = Cl-, BF4-, PF6-, BArf-; 61-84%) are prepared from (η5-C5Me5)Ru(PPh3)2(Cl), GBI, and CO followed (for the last three) by anion metatheses. An indenyl complex [(η5-C9H7)Ru(PPh3)(GBI)]+Cl- (96%) is prepared from (η5-C9H7)Ru(PPh3)2(Cl) and GBI. All complexes are characterized by NMR (1H, 13C, 31P, 19F, 11B), with 2D spectra aiding assignments. Crystal structures of 1+PF6-·CH2Cl2 and 1+BArf-·CH2Cl2 are determined; the anion is hydrogen bonded to the cation in the former. Complexes 1-3+X- are evaluated as catalysts (10 mol %, RT) for condensations of indoles and trans-β-nitrostyrene. The chloride salts are ineffective (0-5% yields, 48-60 h), but the BArf- salts exhibit excellent reactivities (97-46% yields, 1-48 h), with the BF4- and PF6- salts intermediate. Evidence for hydrogen bonding of the nitro group to the GBI ligand is presented. GBI shows no catalytic activity; a BArf- salt of methylated GBI is active, but much less so than 2-3+BArf-.

Strategic Stereoselective Halogen (F, Cl) Insertion: A Tool to Enhance Supramolecular Properties in Polyols

To improve the supramolecular properties of organic compounds, chemists continuously need to identify new tools. Herein, the influence of the stereoselective insertion of halogen atoms (F or Cl) on different supramolecular properties is analyzed. Insertin

Reaction Progress Kinetics Analysis of 1,3-Disiloxanediols as Hydrogen-Bonding Catalysts

1,3-Disiloxanediols are effective hydrogen-bonding catalysts that exhibit enhanced activity relative to silanediols and triarylsilanols. The catalytic activity for a series of 1,3-disiloxanediols, including naphthyl-substituted and unsymmetrical siloxanes, has been quantified and compared relative to other silanol and thiourea catalysts using the Friedel Crafts addition of indole to trans-β-nitrostyrene. An in-depth kinetic study using reaction progress kinetic analysis (RPKA) has been performed to probe the catalyst behavior of 1,3-disiloxanediols. The data confirm that the disiloxanediol-catalyzed addition reaction is first order in catalyst over all concentrations studied with no evidence of catalyst self-association. 1,3-Disiloxanediols proved to be robust and recoverable catalysts with no deactivation under reaction conditions. No product inhibition is observed, and competitive binding studies with nitro-containing additives suggest that 1,3-disiloxanediols bind weakly to nitro groups but are strongly activating for catalysis.

Electrostatically Enhanced Thioureas

A new class of readily prepared thiourea catalysts with one or more positively charged centers and no new hydrogen-bonding sites are exploited in several bond-forming reactions and are orders of magnitude more reactive than Schreiner's thiourea. These fin

De Novo Tailoring Pore Morphologies and Sizes for Different Substrates in a Urea-Containing MOFs Catalytic Platform

To better understand the structure-catalytic property relationship, a platform of urea-containing MOFs with diverse topologies as hydrogen-bonding (H-bond) catalyst has been well established in the present work. During the construction of MOFs, we proposed a new strategy called the isoreticular functionalization approach in which the desired topological net is first considered as a blueprint, and then two predesigned functionalized polydentate ligands link to four different metal clusters by de novo routes to achieve the MOFs with expected pore structure and catalytic sites. By means of this strategy, we successfully synthesized four programmed MOFs (named as URMOF-1-4) with diverse topologies, pore morphologies, and sizes and distribution of active sites. Subsequently, we systematically investigated the Friedel-Crafts reactions of 1-methylpyrrole or 1-methylindole with nitroalkene derivatives with diverse sizes to assess the catalytic properties of the above-mentioned URMOFs. These four URMOFs can act as reusable H-bond catalysts and show varied catalytic capacities and size-selectivity properties. Most significantly, the open morphologies of pores, large channels in the framework, and effective distribution of active sites on the wall of the channel are proved to facilitate catalysis. This urea-containing MOF catalytic platform provides new insight into the catalytic properties of MOFs with the same kind of active sites but diverse topologies, pore morphologies, and sizes and distributions of catalytic sites.

Efficient iron-catalyzed Michael addition of indole to nitroolefins under solvent-free conditions

Iron trichloride hexahydrate has proved to be an effective catalyst for Michael addition of indole to nitroolefins under solvent-free conditions to produce the corresponding adducts with appreciable yields. Graphical Abstract: Solvent-free Michael additio

Electron-withdrawing trifluoromethyl groups in combination with hydrogen bonds in polyols: Bronsted acids, hydrogen-bond catalysts, and anion receptors

Electron-withdrawing trifluoromethyl groups were characterized in combination with hydrogen-bond interactions in three polyols (i.e., CF 3CH(OH)CH2CH(OH)CF3, 1; (CF3) 2C(OH)C(OH)(CF3)2