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The chemoselectivity of hydrodechlorination in 2-chloropyridine derivatives possessing reduction-sensitive functionalities is examined. The reaction conditions employed tolerate a variety of functionalities illustrating highly chemoselective hydrodechlorination in the presence of nitrile, allyl, terminal olefin, and nitroamine functionalities in excellent yield. Chemoselective deprotection of carboxybenzyl ethers is illustrated in moderate yield. [ABSTRACT FROM AUTHOR]

A new method was adopted for the synthesis of benzo[b]carbazoles by Claisen condensation followed by Fischer indole cyclization. Newly synthesized benzo[b]carbazoles were treated with ethanol amine in the presence of polyphosphoric acid which leads to the formation of pyrazino carbazoles. All the synthesized compounds were characterized by all spectral means. [ABSTRACT FROM AUTHOR]

A unique synthesis of aryl methyl sulfides is reported proceeding via reduction of dimethylsulfoxide to dimethylsulfide at elevated temperature in the presence of Hunig’s base followed by nucleophilic aromatic substitution and demethylation. Activated aryl fluorides, chlorides, and nitrobenzenes are suitable substrates with 13 examples provided. Dimethylsulfoxide serves as a simple and inexpensive formal source of the thiomethyl moiety. [ABSTRACT FROM AUTHOR]

The secondary amines synthesized by the reaction between 2-aminophenols and aromatic aldehydes, via the reduction of the corresponding imines, were employed in the synthesis of new 2-hydroxy-2 H -1,4-benzoxazine derivatives through a one-pot Petasis multicomponent reaction in good to excellent yields. [ABSTRACT FROM AUTHOR]

A novel and efficient method has been developed for the chemoselective conjugate reduction of α,β-unsaturated ketones with tosylhydrazine as a hydrogen source to the corresponding saturated ketones in moderate to good yields. The present protocol does not require the use of transition metal, and is efficient being applicable to a wide range of substrates (25 examples). [ABSTRACT FROM AUTHOR]

Abstract: The selective cleavage of different benzyl bonds within tetrahydroquinazoline and dihydroquinazolinone derived structures can be achieved by the usage of different reduction and debenzylation conditions thereby providing selective removal of O-benzyl protection groups as well as the cleavage of the ring structure within the quinazoline and quinazolinone systems. [Copyright &y& Elsevier]

Abstract: Titanium(IV) halides are extensively used in carbon carbon bond forming reactions as a Lewis acid and low valent titanium halides promote reductive coupling reactions of carbonyl compounds. In most of these reactions, ligands of titanium halides are chloride or bromide. On the other hand, titanium(IV) tetraiodide had been rarely used in organic synthesis until the late 1990s. Since 2000 several useful synthetic reactions have been developed utilizing a moderate Lewis acidity, reducing and iodination abilities of titanium(IV) tetraiodide. This digest summarizes examples of chemoselective reductions and iodinations using titanium(IV) tetraiodide (TiI4). [Copyright &y& Elsevier]

Abstract: An operationally simple, economical, and straightforward synthesis of diverse 4,5-disubstituted 1,2,3-thiadiazoles from α-enolicdithioesters has been achieved via nitrosation/reduction/diazotization/cyclization sequence in one-pot through the formation of cascade 1–2 (N–S) and 3–4 (C–N) bonds. Importantly, this is the first straightforward entry to highly functionalized 1,2,3-thiadiazoles from dithioesters. [Copyright &y& Elsevier]

Abstract: Direct reductive amination (DRA) using triethylsilane (TESH) and catalytic bismuth(III) chloride (BiCl3) is described for the first time. The use of TESH and BiCl3 provides easy handling, low cost, non-toxicity, and a mild Lewis acid activity, thereby meeting the demand for green and sustainable chemistry. The developed DRA is highly chemoselective and applicable to less-basic amines. The experimental results of this study revealed that the developed DRA could be catalyzed by BiCl3, which was gradually reduced to Bi(0) or bismuth with a low valency by TESH, but TESCl, Bi(0), and Bi(0) with TESCl catalyzed the DRA to some extent. [Copyright &y& Elsevier]

Abstract: A new method has been developed for the generation and subsequent reaction of ynolates in a micro flow reactor system. This new procedure allowed for ynolates to be prepared at 0°C or ambient temperature within 1min via a reductive lithiation reaction, whereas the corresponding batch processes generally require low temperature control and extended reaction times of up to 1h. The resulting ynolates were applied to the olefination of carbonyl compounds, with the reactions reaching completion in a much shorter reaction time in the continuous flow reactor than the batch reactor. These results highlight the practical utility of the ynolate reaction, and represent the first reported example of the use of lithium naphthalenide in a flow microreactor, which would contribute to progress of the flash chemistry. [Copyright &y& Elsevier]

Abstract: Targeted inactivation of the mpp7 gene in the Monascus azaphilone pigment (MAzP) biosynthetic gene cluster resulted in the accumulation of monasfluol A (7) and B (8), of which the latter was a novel compound, and the abolition of the main MAzPs. It is thus proposed that 7 and 8 are the products of non-enzymatic Knoevenagel condensation followed by a reduction and that Mpp7 assists in regioselective Knoevenagel aldol condensation during MAzP biosynthesis. [Copyright &y& Elsevier]

Abstract: The reaction of imines with low-valent titanium species, generated in situ by using Ti(O i Pr)4/2 c-C5H9MgCl reagent, affords titanium–imine complex, which can couple with nitriles to provide 2,5-diazatitanacyclopentenes. α-Aminoketones are obtained in good yields by quenching the corresponding 2,5-diazatitanacyclopentenes with aqueous HCl solution. However, when the reaction is first quenched with MeOH in air followed by addition of aqueous HCl solution, 1,2-diketones are formed in good to high yields. [Copyright &y& Elsevier]

Abstract: A Pd-catalyzed method for the preparation of imidazolinium salts from the corresponding thioureas that could then be used for the synthesis of imidazolium and amidinium salts is described. This method has great potential because all the required reagents are readily available and thioureas are safely converted to their corresponding precursors of NHCs under mild conditions. [Copyright &y& Elsevier]

Abstract: A highly stereoselective Michael reduction/intramolecular Michael reaction cascade is described. The cascade is initiated by the regioselective Michael reduction of an α-methylidene ester with L-Selectride. This is followed by the highly stereoselective intramolecular Michael reaction which efficiently constructs a six-membered carbocyclic ring with formation of the trans-stereodiad, composed of an all-carbon quaternary center and a tertiary stereogenic center. The stereoselectivity is perfectly controlled by the choice of alkene geometry in the Michael acceptor. [Copyright &y& Elsevier]

Highlights: [•] The photooxygenation of novel sugar-furans followed by sulfide reduction is reported. [•] Novel spiroketals of monosaccharides are synthesized through a one-pot procedure. [•] The synthetic strategy presented for spiro compounds is based on a green process. [•] The synthesis of novel furyl ketoses is depicted. [ABSTRACT FROM AUTHOR]

Abstract: Herein, we have developed a mild and selective reductive deprotection method for the MAc protected alcohols using sodium borohydride. The new deprotection conditions provide a complete orthogonality between O-MAc and other protecting groups such as tert-butyl ester, N-Boc, Fmoc, Cbz, O-TBDMS, N-benzyl, O-benzyl, O-acetyl, N-acetyl, N-MAc, etc. In addition to O-MAc deprotection, this method is also applicable for S-MAc deprotection. [Copyright &y& Elsevier]

Abstract: In the present Letter several carbolactones (oxidative products) are obtained under aprotic cathodic conditions in the preparative scaled electrolysis of 1,2-quinones in a divided electrochemical cell and in the presence of oxygen. When 9,10-phenanthrenequinone is reduced 6H-dibenzo[b,d]pyran-6-one and [1,1′-biphenyl]-2,2′-dicarboxylic acid are obtained as major products. In the reduction of 1,2-naphthoquinone, 2-benzopyran-1(1H)-one, and 2-(2-carboxyethenyl)-benzoic acid were formed as main products. The proposed mechanism to explain the formation of these and other products, that involves an electron-transfer reaction to the oxygen in air, is now discussed. [Copyright &y& Elsevier]

Abstract: A simple and convenient method for the chemoselective reduction of nitriles into aldehydes using a 1,1,3,3-tetramethyldisiloxane (TMDS)/triisopropoxyvanadium(V) oxide reducing system is described. Aromatic as well as aliphatic nitriles are reduced into the corresponding aldehydes in moderate to good yields. [Copyright &y& Elsevier]

Abstract: A simple synthesis of 3-iodothiophenes was demonstrated using a wide range of ( Z )-thioenynes. The key step in the iodocyclofunctionalization was the selective reduction of the triple bond in ( Z )-thioenynes by the addition of iodine as an electrophilic agent. The 3-iodothiophenes were obtained in good to excellent yields of 61–92%. The 3-iodothiophenes were used as substrates in Sonogashira cross-coupling reactions to obtain thiophene acetylenes. [Copyright &y& Elsevier]

Abstract: Use of aluminium as the reducing metal in spontaneous bimetal redox reaction has been elegantly exploited for allylation/crotylation of aldehydes in wet solvent. Here, low valent tin was prepared in situ by reduction of SnCl2·2H2O with aluminium in THF/water. The resulting low valent tin acted as an efficient mediator for allylation and crotylation of aldehydes (3a–q) producing the corresponding homoallylic alcohols. The efficacy of this procedure was due to its operational simplicity, practical viability, inexpensiveness, good yields of the products and short reaction time. [Copyright &y& Elsevier]

Abstract: Ethyl 3,5-diaryl-1H-pyrrole-2-carboxylates have been synthesized in good yields from ethyl 2-nitro-5-oxo-3,5-diarylpentanoates by treatment with triethylphosphite under microwave irradiation. The integrity of the mechanism proposed has been augmented by 31P NMR and EIMS experiments. [Copyright &y& Elsevier]

Abstract: The reaction of dihydroartemisinin (DHA) with solvated electrons ( ) generated under radiolytic conditions showed high pH dependence. The reduction performed under neutral conditions led to the formation of compound P1 deriving from the initial alkoxyl radical as the only detectable product. [Copyright &y& Elsevier]

Abstract: A concise and high-yielding protocol for the synthesis of 5,6-dihydrophenanthridines is disclosed. The key feature includes a sequential reduction-cyclization reaction of N-acylcarbamates via N,O-acetal TMS ethers as a stable N-acyliminium ion precursor. [Copyright &y& Elsevier]

Abstract: An expeditious and practical method for the reduction of amides to amines is reported. The method consists of activation of amides with TMSCl followed by reduction with LiAlH4. Various amides/lactams including hindered amides and secondary amides gave the corresponding amines in good to excellent yields. This novel protocol has a wide substrate scope and shows good functional group tolerance with high stereoretention. [Copyright &y& Elsevier]

Abstract: The first stereocontrolled synthesis of the title δ-aminoboronic esters—proceeding from commercially available nitriles—via a reduction, Brown’s ‘allyl’ boration reaction, a Boc-protection, a hydroboration, an oxidative elimination of α-pinene, and an esterification reaction, has been reported in excellent enantio- and diastereoselectivities. [Copyright &y& Elsevier]

Abstract: A new 2′-OH protecting group, {[2,2-dimethyl-2-(2-nitrophenyl)acetyl]oxy} methyl (DAM), has been successfully applied to RNA oligonucleotides synthesis with high coupling efficiency. The 2′-O-DAM method is fully compatible with reagents and conditions employed in automated solid phase synthesis of RNA. Moreover, it can be easily removed via reduction in near-neutral solution. [Copyright &y& Elsevier]

Abstract: A series of enantiomerically pure tridentate ligands based on the 1,2-diphenylethane-1,2-diamine structure, containing additional pyridine groups, was prepared and tested in asymmetric transfer hydrogenation of ketones using Ru3(CO)12 as a metal source. Alcohols were formed in up to 93% ee in the best cases, and good results were obtained with ortho-haloarylketones. [Copyright &y& Elsevier]

Abstract: A series of bis-Salen Mn(III) chiral complexes of rigid structure axially coordinated with bis-diphenolate and bis-diamine ligands were synthesized and their catalytic performances in asymmetric epoxidation of indene and α-methylstyrene were investigated in detail. Compared with Jacobsen’s catalyst and the corresponding monomer salen Mn(III) catalyst, bis-Salen Mn complex showed higher activity and enantioselectivity under the same reaction conditions. A point worth emphasizing was that the bis-diphenolate axially coordinated bis-Salen Mn catalysts afforded remarkable increases of ee values in the absence of axial base NMO for the asymmetric epoxidation of olefins, especially for the epoxidation of indene (ee: from 55% to 100%), however, the axial base is indispensable for the bis-diamine axially coordinated bis-Salen Mn(III) catalysts, these performance might attribute to the rigid difference of the structure. Furthermore, the catalyst could be conveniently recovered and reused at least five times without significant losses of both activity and enantioselectivity. Specially, it could also be efficiently used in large-scale reactions with superior catalytic disposition being maintained at the same level, which possessed the potentiality for application in industry. [Copyright &y& Elsevier]

Abstract: Two room temperature liquid salts containing molybdenum(VI), [BMIM]2[MoO2(NCS)4] (1) and [DMIM]2[MoO2(NCS)4] (2), were immobilized on ionic liquid-modified silica leading to materials which showed notable catalytic activity for the reduction of sulfoxides into sulfides with triphenylphosphine (PPh3). The molybdenum liquid salts immobilized on the supported ionic liquid phase could be reused at least for three catalytic cycles without significant loss of activity. [Copyright &y& Elsevier]

Abstract: Resting cells of Kluyveromyces marxianus were used in the bioreduction of ethyl 4,4,4-trifluoro-3-oxobutanoate and ethyl 4,4,4-trichloro-3-oxobutanoate with 81% and 4% yields and 29% and 73% enantiomeric excess, respectively. The differences observed were attributed to the tri-halide structures. [Copyright &y& Elsevier]

Abstract: An efficient protocol for deoxygenation of α,β-unsaturated acylphenols through ethyl o-acylphenylcarbonates with Luche reduction is described. The reaction shows very good selectivity and tolerates a wide range of functionalities on α,β-unsaturated acylphenols, giving corresponding 2-allylphenols in good to excellent yields. [Copyright &y& Elsevier]

Abstract: Herein, conditions for the fast and effective reduction of aromatic nitro groups bound to hydrophobic polystyrene-based Wang and Ring resins utilizing sodium dithionite in dichloromethane–water under PTC conditions are reported. Tetrabutylammonium hydrogen sulfate (TBAHS) was found to be an effective phase-transfer catalyst for this reaction. This method allows for the reduction of nitro groups to amino groups under mild conditions with complete conversion and is tolerant of other functional groups. This method is a superior alternative to tin(II) chloride-based reduction, which is known for its shortcomings. [Copyright &y& Elsevier]

Abstract: An efficient method to effect selective reduction of several structurally diverse dienes and an unsymmetrical triene is reported. The reduction is facile at 0°C in a liquid amide aqueous solution containing sodium borohydride in the presence of 15mol% ruthenium(III) chloride. The chemoselectivity of the reaction is controlled by proper choice of the liquid amide solvent. [Copyright &y& Elsevier]

Abstract: A novel reduction/elimination method of thiazolidine-2,4-dione and imidazolidine-2,4-dione derivatives using Schwartz reagent to synthesize numerous thiazolones and imidazolones in a single step is reported. [Copyright &y& Elsevier]

Abstract: The first asymmetric reduction of ketimines with catecholborane employing an enantiopure N-triflyl phosphoramide as the organocatalyst has been developed. Five mole% of the catalyst provides the corresponding secondary amines in very good to almost quantitative yields and good enantioselectivities up to 86:14 e.r. under mild reaction conditions. [Copyright &y& Elsevier]

Abstract: We report on a novel synthetic procedure to obtain β-aminoporphyrins with zinc(II) as the metal center by using the catalytic reduction of the parent Zn(II)β-nitroporphyrins with hydrogen in the presence of Pd/C using dimethylformamide as the solvent. This simple method allows the preparation of β-aminoporphyrins with substituents with diverse electronic properties: meso-tetraphenylporphyrin (TPP), meso-tetrakis(2,6-dichlorophenyl)porphyrin (TDCPP), and meso-tetrakis(2,3,4,5,6-pentafluorophenyl)porphyrin (TPFPP). [Copyright &y& Elsevier]

Abstract: Treatment of a range of trisubstituted β,γ-unsaturated esters with 2equiv of (−)-monoisopinocampheylborane results in hydroboration of their alkene functionalities and reduction of their ester groups to afford chiral 1,3-diols containing two new vicinal β,γ-(anti)-stereocentres in 67–85% enantiomeric excess. [Copyright &y& Elsevier]

Abstract: The total synthesis of Resolvin D1, a potent endogenous anti-inflammatory lipid mediator derived from docosahexaenoic acid, has been achieved. The chiral hydroxy-groups at C7, C8 and C17 were obtained via a chiral pool strategy from 2-deoxy-d-ribose. Wittig reactions followed by a modified Pd0/CuI Sonogashira coupling and Zn(Cu/Ag) cis-reduction completed the total synthesis of Resolvin D1. [Copyright &y& Elsevier]

Abstract: A convenient in situ method is described for reductive removal of the amino group in position 1 of the anthraquinone (AQ) moiety. The reaction proceeds smoothly within a few minutes yielding novel AQ derivatives in excellent yields. Diazonium salt formation is followed by reduction with zinc in ethanol. The method has been applied to a variety of 1-amino-AQ derivatives. It allows access to a large library of new AQ derivatives which possess potential as pharmacological tools for studying purinergic signaling, and as potential drugs, for example, for the treatment of cancer and cardiovascular diseases. [Copyright &y& Elsevier]

Abstract: Upon the one-electron reduction of N-methylquinoxalino[2,3-b]quinoxaliniums 2, neutral radicals 1 without any bulky protecting groups were generated and isolated as stable solids, which exhibit electric conductivity (σ =10−7−10−9 Scm−1) as a single-component organic material due to high electrochemical amphotericity (ΔE =ca. 0.9V). [Copyright &y& Elsevier]

Abstract: Mg-Promoted reductive coupling of azulene with various α,β-unsaturated ketones in the presence of chlorotrimethylsilane in 1-methyl-2-pyrrolidinone brought about regioselective formation of the corresponding 6-substituted dihydroazulenes, which were easily oxidized to the corresponding 6-substituted azulenes by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in good yields. This new regioselective method enabled us to synthesize various 6-substituted azulenes from azulene in only two steps. [Copyright &y& Elsevier]

Abstract: A novel pyrimido[4,5-b][1,4]diazepine-2,4,6-trione was synthesized with an efficient strategy. Especially, the key intermediate 2,4-dimethoxypyrimido[4,5-b][1,4]diazepin-6-one was promoted by one pot tandem reduction–cyclization with Na2S2O4. Subsequently, reduction of lactams 6 with LiAlH4 afforded a more flexible scaffold of pyrimidodiazepines. The synthetic strategy was versatile since it facilitated the sequential functionalization on the pyrimidodiazepine at three positions. Thus a convenient and effective method for the rapid preparing of multi-substituted pyrimido[4,5-b][1,4]diazepines was developed. [Copyright &y& Elsevier]

Abstract: A simple and efficient method for the synthesis of alcohols from the corresponding carboxylic acids is described. Activation of carboxylic acid with 1-propanephosphonic acid cyclic anhydride (T3P) and subsequent reduction using NaBH4 yield the alcohol in excellent yields with good purity. Reduction of several alkyl/aryl carboxylic acids and Nα-protected amino acids/peptide acids as well as Nβ-protected amino acids was successfully carried out to obtain corresponding alcohols in good yields. All the products were fully characterized by 1H NMR and mass spectral analyses. The procedure is mild, simple and the isolation of the products is easy. [Copyright &y& Elsevier]

Abstract: The reductive etherification of aldehydes can be performed by the reaction with dialkylmethylsilanes in the presence of new iron(II) piano-stool catalysts of general formula Cp∗Fe(CO)2Ar (Cp∗ =η5-C5Me5; Ar=Ph, 4-C6H4OCH3, 4-C6H4CH3, Fc). This transformation is promoted by UV light and affords a simple route for the preparation of unsymmetrical alkyl ethers. [Copyright &y& Elsevier]

Abstract: Classically, 2,1-benzisoxazoles (anthranils) are prepared from 2-nitroacylbenzenes by a reductive heterocyclization reaction with Sn or SnCl2 concentrated HCl. Acid sensitive functionalities are expected to be incompatible with these conditions; milder approaches to the synthesis of 2,1-benzisoxazoles would be welcomed. We demonstrate that SnCl2·2H2O in a 1:1 mixture of EtOAc/MeOH is capable of mediating the tandem reduction–heterocyclization of a variety of 2-nitroacylbenzenes to their corresponding 2,1-benzisoxazoles in good to excellent yields under essentially neutral conditions. Importantly, several commonly used acid–labile protecting groups, including Boc carbamate, tert-butyl ether, and tert-butyl ester, proved orthogonal to these reaction conditions. [Copyright &y& Elsevier]

Abstract: The three-component direct Mannich reaction between aldehydes, p-toluenesulfonamide, and enolizable ketones was achieved for the first time with organic bases as the catalysts. The corresponding N-tosylated β-aminoketones were obtained in high yields and good to excellent diastereoselectivities using TMG as the catalyst. Through reduction of the ketone group, the reaction product may be converted into β-aminol with excellent diastereoselectivity. [Copyright &y& Elsevier]

Abstract: Solid supported palladium(0) (SS-Pd) catalyzed highly chemoselective reduction of nitroarenes to the corresponding anilines was accomplished under a milder reaction condition. This catalyst showed high compatibility with various reducing agents (NaBH4, Et3SiH, and NH2NH2·H2O) and a large number of reducible functional groups such as sulfonamide, amides, carboxylic acid, ester, alcohol, halide, hetero cycle, nitrile, alkene, carbonyl, O-benzyl, and N-benzyl were tolerated. Most of the reactions were clean and high yielding. The SS-Pd catalyst could be recycled up to seven runs without significant loss of activity. [Copyright &y& Elsevier]

Abstract: The enantioselective synthesis of oxylipin-3 has been carried out. The synthetic strategy was started from commercially available n-decanal. The chiral source was based on Sharpless asymmetric dihydroxylation and CBS reduction. [Copyright &y& Elsevier]

Abstract: A straightforward method of creating a bifunctional support possessing pre-defined ratios of amine and chloromethyl groups based upon a controlled conversion of standard Merrifield resin is presented. It avoids the extensive optimisation of reactant concentrations and reaction conditions required by existing methods. Furthermore, it avoids increases in the spacer/linker length that lead to detrimental reductions in the rigidity of the grafted layer. The method will allow for efficient, predictable and reproducible co-immobilisation of molecular species. [Copyright &y& Elsevier]

Abstract: Treatment of halogen-heteroaromatic aldehydes with catalytic amount of PdCl2 under atmosphere pressure of hydrogen in base medium (sodium acetate) leads to the corresponding dehalogenated primary alcohols. The reaction system was especially effective for the heteroaromatic compounds bearing aldehyde groups and halides (bromo- or chloro-functions). [Copyright &y& Elsevier]