Simple Alcohols Research Articles

T3P®-assisted esterification and amidation of phosphinic acids

A few phosphinic acids, such as phenylphosphinic acids, 1-hydroxy-3-phospholene 1-oxides and 1-hydroxyphospholane oxides are esterified with simple alcohols in the presence of propylphosphonic anhydride (T3P®). If 1.1 equiv of the T3P® reagent is used, the esterifications are fast and efficient at 25° C. In the case of more reactive models it was enough to apply 0.66 equiv of T3P® at 85° C under microwave conditions. The amidation of 1-hydroxy-3-methyl-3-phospholene oxide could also be accomplished under similar conditions.

Sulfonic acid-functionalized MIL-101(Cr): An efficient catalyst for esterification of oleic acid and vapor-phase dehydration of butanol

A highly porous and acidic metal-organic framework (MOF), MIL-101(Cr)-SO3H, was hydrothermally synthesized in one step using sulfonic acid-functionalized ligands. The prepared catalysts were systematically characterized with X-ray diffraction, FTIR, nitrogen adsorption, and thermogravimetric analysis. MIL-101(Cr)-SO3H was successfully used in the liquid-phase reaction (esterification of oleic acid), and also applied for the first time in the vapor-phase (2-butanol dehydration) reaction. The esterification is catalyzed in the heterogeneous mode, as confirmed by a negligible increase in the esterification yield after the filtration of the catalyst. The esterification was performed under both microwave (MW) and conventional heating (CE), and a beneficial effect of the MW reaction for rapid reactions was observed. The vapor-phase dehydration of 2-butanol to olefins (BTO) over MIL-101(Cr)-SO3H was very stable in conversion, which is different from the results obtained using the SAPO-34 molecular sieve, which has been widely used in the dehydration of simple alcohols. The obtained results demonstrated the versatile applicability of the sulfonic acid-functionalized MOFs both in the liquid- and vapor-phase reactions.

Highly Efficient Direct Allylation of Oxindoles with Simple Allylic Alcohols Enabled by Palladium/Brønsted Acid Catalysis

A highly efficient and practical direct allylic alkylation of oxindoles with simple allylic alcohols cocatalyzed by Pd(OAc)₂/Ph₃P and PhCO₂H under mild conditions has been developed, which streamlines the installation of an all-carbon quaternary allylic center at the oxindole 3-position. Enantioselective allylic alkylation has also been realized with the product in almost quantitative yield and 17% enantiomeric excess. Mechanistically, ESI analysis indicates that a palladium(0) species and π-allyl-Pd(PPh₃)₂ cation were involved.

ChemInform Abstract: Combined Heterogeneous Metal/Chiral Amine: Multiple Relay Catalysis for Versatile Eco‐Friendly Synthesis.

Herein is described a versatile and broad synergistic strategy for expansion of chemical space and the synthesis of valuable molecules (e.g. carbocycles and heterocycles), with up to three quaternary stereocenters, in a highly enantioselective fashion from simple alcohols (31 examples, 95:5 to >99.5:0.5 e.r.) using integrated heterogeneous metal/chiral amine multiple relay catalysis and air/O₂ as the terminal oxidant. A novel highly 1,4-selective heterogeneous metal/amine co-catalyzed hydrogenation of enals was also added to the relay catalysis sequences.

A Robust Nanoporous Supramolecular Metal–Organic Framework Based on Ionic Hydrogen Bonds

Hydrogen-bond assembly of tripod-like organic cations [H3 -MeTrip](3+) (1,2,3-tri(4'-pyridinium-oxyl)-2-methylpropane) and the hexa-anionic complex [Zr2 (oxalate)7 ](6-) leads to a structurally, thermally, and chemically robust porous 3D supramolecular framework showing channels of 1 nm in width. Permanent porosity has been ascertained by analyzing the material at the single-crystal level during a sorption cycle. The framework crystal structure was found to remain the same for the native compound, its activated phase, and after guest resorption. The channels exhibit affinities for polar organic molecules ranging from simple alcohols to aniline. Halogenated molecules and I2 are also taken up from hexane solutions by this unique supramolecular framework.

Ruthenium-catalyzed N-alkylation of amines with alcohols under mild conditions using the borrowing hydrogen methodology.

Using a simple amino amide ligand, ruthenium-catalyzed one-pot alkylation of primary and secondary amines with simple alcohols was carried out under a wide range of conditions. Using the alcohol as solvent, alkylation was achieved under mild conditions, even as low as room temperature. Reactions occurred with high conversion and selectivity in many cases. Reactions can also be carried out at high temperatures in organic solvent with high selectivity using stoichiometric amounts of the alcohol.

ChemInform Abstract: Ni‐Catalyzed Carboxylation of C(sp2)— and C(sp3)—O Bonds with CO2.

In recent years a significant progress has been made for the carboxylation of aryl and benzyl halides with CO2, becoming convenient alternatives to the use of stoichiometric amounts of well-defined metal species. Still, however, most of these processes require the use of pyrophoric and air-sensitive reagents and the current methods are mostly restricted to organic halides. Therefore, the discovery of a mild, operationally simple alternate carboxylation that occurs with a wide substrate scope employing readily available coupling partners will be highly desirable. Herein, we report a new protocol that deals with the development of a synergistic activation of CO2 and a rather challenging activation of inert C(sp2)–O and C(sp3)–O bonds derived from simple and cheap alcohols, a previously unrecognized opportunity in this field. This unprecedented carboxylation event is characterized by its simplicity, mild reaction conditions, remarkable selectivity pattern and an excellent chemoselectivity profile using air-,...

Structure–activity relationships on metal-oxides: alcohol dehydration

The Lewis-acid catalyzed dehydration of simple alcohols on TiO2, ZrO2 and γ-Al2O3 oxide-catalysts has been investigated by combining ab initio theoretical calculations with temperature programmed desorption (TPD) experiments. Both theoretical and experimental results demonstrate that γ-Al2O3 is more active in catalyzing the dehydration reactions than either TiO2 or ZrO2. The dehydration reaction occurs through an E2-elimination mechanism involving either surface O and/or OH groups of the oxides. Based on relationships between the dehydration barriers and key properties of the alcohols and the oxides, a dehydration model was developed that is able to screen the dehydration performance of various alcohols on different metal oxides and provide predictions that were in good agreement with the experimental dehydration barriers. The model accounts for the effect of surface hydration and the existence of surface OH-groups. The basicity of the surface oxygens is shown to be important in eliminating beta hydrogens of the alcohols. This work highlights the importance of surface OH-groups as active centers for the elimination of beta hydrogens of alcohols in Lewis-acid catalyzed dehydration reactions, a result different from the conventional view that surface OH-groups are associated with Bronsted acidity. Most importantly, a novel methodology is introduced that develops structure–activity relationships on oxides for the conversion of biomass derived molecules to chemicals.

A free radical cascade cyclization of isocyanides with simple alkanes and alcohols.

A copper-catalyzed free-radical cascade cyclization of isocyanides with simple alkanes and alcohols was developed, which allowed convenient access to various alkyl-substituted phenanthridines.

Auxin Input Pathway Disruptions Are Mitigated by Changes in Auxin Biosynthetic Gene Expression in Arabidopsis.

Auxin is a phytohormone involved in cell elongation and division. Levels of indole-3-acetic acid (IAA), the primary auxin, are tightly regulated through biosynthesis, degradation, sequestration, and transport. IAA is sequestered in reversible processes by adding amino acids, polyol or simple alcohols, or sugars, forming IAA conjugates, or through a two-carbon elongation forming indole-3-butyric acid. These sequestered forms of IAA alter hormone activity. To gain a better understanding of how auxin homeostasis is maintained, we have generated Arabidopsis (Arabidopsis thaliana) mutants that combine disruptions in the pathways, converting IAA conjugates and indole-3-butyric acid to free IAA. These mutants show phenotypes indicative of low auxin levels, including delayed germination, abnormal vein patterning, and decreased apical dominance. Root phenotypes include changes in root length, root branching, and root hair growth. IAA levels are reduced in the cotyledon tissue but not meristems or hypocotyls. In the combination mutants, auxin biosynthetic gene expression is increased, particularly in the YUCCA/Tryptophan Aminotransferase of Arabidopsis1 pathway, providing a feedback mechanism that allows the plant to compensate for changes in IAA input pathways and maintain cellular homeostasis.

ChemInform Abstract: Palladium‐Catalyzed Intermolecular [3 + 2] Carbocyclization of Alkynols and Propiolates: An Efficient Entry to Halo‐Cyclopentadienes.

AbstractThe title reaction employs simple propargyl alcohols (I) as C3 building block to participate in the cyclization reaction, providing a convenient and atom‐economical entry to the halo‐cyclopentadiene framework.

Asymmetric α-Allylation of α-Branched Aldehydes with Allyl Alcohols by Synergistic Catalysis Using an Achiral Palladium Complex and a Chiral Primary Amino Acid

Highly enantioselective direct α-allylation of α-branched aldehydes with simple allyl alcohols was achieved by the combined use of an achiral transition-metal catalysis with a palladium complex and a chiral organocatalysis with a readily obtainable primary α-amino acid. Various α-allylated aldehydes possessing a stereocontrolled quaternary carbon stereogenic center were synthesized in high yields with high enantioselectivity.

Substitution Controlled Functionalization ofortho-Bromobenzylic Alcohols via Palladium Catalysis: Synthesis of Chromenes and Indenols

An efficient domino Pd-catalyzed transformation of simple ortho-bromobenzyl tertiary alcohols to chromenes is presented. Their formation is believed to proceed via the formation of a five-membered palladacycle, which, in turn, involves in an intermolecular homocoupling with the second ortho-bromobenzyltertiary alcohol to yield the homo-biaryl bond followed by intramolecular C-O bond formation. Interestingly, when there is an allylic substituent on the benzylic carbon atom, a chemoselective switch was observed, which preferred intramolecular Heck coupling and gave indenols. Further, it has been confirmed that the tertiary alcohol functionality is indispensible to give the coupled products, whereas the use of primary/secondary benzylic alcohols furnished the simple carbonyl products via a possible reductive debromination followed by oxidation due to the availability of β-hydrogen(s).

Combined Heterogeneous Metal/Chiral Amine: Multiple Relay Catalysis for Versatile Eco‐Friendly Synthesis

Herein is described a versatile and broad synergistic strategy for expansion of chemical space and the synthesis of valuable molecules (e.g. carbocycles and heterocycles), with up to three quaternary stereocenters, in a highly enantioselective fashion from simple alcohols (31 examples, 95:5 to >99.5:0.5 e.r.) using integrated heterogeneous metal/chiral amine multiple relay catalysis and air/O₂ as the terminal oxidant. A novel highly 1,4-selective heterogeneous metal/amine co-catalyzed hydrogenation of enals was also added to the relay catalysis sequences.

Comparative studies on the O-sialylation with four different α/β-oriented (N-acetyl)-5-N,4-O-carbonyl-protected p-toluenethiosialosides as donors

Four types of 5-N,4-O-carbonyl-protected p-toluenethiosialosides were synthesized and their couplings with different acceptors were thoroughly investigated. The results indicate that the sialyl donor structure, the amount of glycosyl acceptor, and the detailed promotion conditions have great influence on the sialylation stereoselectivties and product yields. Under the (p-Tol)2SO/Tf2O activation conditions, the glycosylations with simple alcohols provided declined α-selectivities and higher yields with increasing the amounts of acceptors from 1.1equiv to 2.0equiv. However, the outcome of same sialylation was independent of the relative amounts of sugar alcohol acceptors. With NIS/TfOH as promoter, the α-selectivities of the sialylations were significantly improved compared with the cases activated by (p-Tol)2SO/Tf2O. In general, the difference in configuration of N-acetylated sialyl donors (D2 and D4) has little effect on the sialylation yield and stereoselectivity. In contrast, the N-deacetylated α/β sialyl donors (D1 and D3) show complex sialylation profiles with different acceptors.

Organizational chirality expression as a function of the chirality measure of simple amino alcohols on Cu(100)

Chiral self-assembled molecular networks (SAMNs) are important for technological and fundamental reasons. In spite of the large number of works in this field, the mechanism of chirality transfer from single molecules to large-scale two-dimensional (2D) networks is not fully understood yet. This work reports on the self-assembly of simple amino alcohols with different chirality measures on Cu(100). Ethanolamine (2-amino-1-ethanol), alaninol (2-amino-1-propanol) and butanolamine (2-amino-1-butanol) adsorbed on Cu(100) have been investigated with scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), photoelectron spectroscopy (PES) and density functional theory (DFT) calculations. This study addresses the role of the single-molecule handedness in the global chirality expression, showing how the chirality measure of the precursors plays an important role in the formation of globally chiral superstructures.

ChemInform Abstract: Iron‐Catalyzed One‐Pot 2,3‐Diarylquinazolinone Formation from 2‐Nitrobenzamides and Alcohols.

AbstractThis method is suitable for benzylic alcohol derivatives (II), but not for simple aliphatic alcohols (e.

Ni-Catalyzed Carboxylation of C(sp2)– and C(sp3)–O Bonds with CO2

In recent years a significant progress has been made for the carboxylation of aryl and benzyl halides with CO2, becoming convenient alternatives to the use of stoichiometric amounts of well-defined metal species. Still, however, most of these processes require the use of pyrophoric and air-sensitive reagents and the current methods are mostly restricted to organic halides. Therefore, the discovery of a mild, operationally simple alternate carboxylation that occurs with a wide substrate scope employing readily available coupling partners will be highly desirable. Herein, we report a new protocol that deals with the development of a synergistic activation of CO2 and a rather challenging activation of inert C(sp(2))-O and C(sp(3))-O bonds derived from simple and cheap alcohols, a previously unrecognized opportunity in this field. This unprecedented carboxylation event is characterized by its simplicity, mild reaction conditions, remarkable selectivity pattern and an excellent chemoselectivity profile using air-, moisture-insensitive and easy-to-handle nickel precatalysts. Our results render our method a powerful alternative, practicality and novelty aside, to commonly used organic halides as counterparts in carboxylation protocols. Furthermore, this study shows, for the first time, that traceless directing groups allow for the reductive coupling of substrates without extended π-systems, a typical requisite in many C-O bond-cleavage reactions. Taking into consideration the limited knowledge in catalytic carboxylative reductive events, and the prospective impact of providing a new tool for accessing valuable carboxylic acids, we believe this work opens up new vistas and allows new tactics in reductive coupling events.

Palladium catalyzed direct allylation of azlactones with simple allylic alcohols in the absence of any activators

The first example of the readily scalable direct allylic alkylation of azlactones with simple allylic alcohols has been developed, which is catalyzed by Pd(PPh3)4 alone in the absence of any activators under neutral conditions.

PdCl2 catalyzed efficient assembly of organic azides, CO, and alcohols under mild conditions: a direct approach to synthesize carbamates

A simple and readily available PdCl2 catalyzed carbamate synthesis method via isocyanate generation and application in situ has been developed. This chemistry provides an efficient and practical approach to synthesize carbamates from simple organic azides, CO atmosphere and alcohols. The broad scope, mild and neutral conditions, and only N2 as the byproduct make this transformation very useful. Moreover, simple examples of modification of bioactive molecules and construction of macrocycles were achieved through this protocol.