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Abstract: A simple and electrolyte-free ion-transfer electrosynthesis micro-reactor system (volume 100μL, up to 10mg batches) for processes at liquid–liquid interfaces is developed and demonstrated for the reduction of aldehydes and imines. These cathodic reactions occur at an amphiphilic carbon nanofiber membrane accompanied by proton cation transfer from an aqueous phase into an organic phase. [Copyright &y& Elsevier]

Abstract: New C-glycosylated N β-protected aza-β3-amino acid building blocks have been prepared from C-glycosyl aldehydes of gluco and galacto configuration by reductive amination and subsequent N-alkylation. These moieties were elaborated to β-dipeptides by elongation at the C- or the N-terminus establishing their ability to be incorporated in original glycosylated foldamers. [Copyright &y& Elsevier]

Abstract: The simple galvanostatic reduction of a solution of MeCN-0.1M Et4NPF6 leads to the formation of acetonitrile anion, whose counter-ion is the Et4N+ cation, which leaves the anion ‘naked’. This enhances the reactivity of acetonitrile anion, which reveals to be selective in the N-monoalkylation of bifunctional compounds (cycloserine, β-amino alcohols, 2-substituted anilines) obtaining high yields. N,N-bis-alkylation has never been observed, indicating that the electrochemical methodology is highly regioselective. [Copyright &y& Elsevier]

Abstract: A general and efficient method for the preparation of spiro compounds is described. Enone–aldehydes were exposed to samarium diiodide under mild conditions and various spirocyclic γ-hydroxyketones were obtained in good yields. [Copyright &y& Elsevier]

Abstract: A novel trans-diastereoselective reductive amination of 4-substituted cyclohexanones is described using 9-BBN as reducing agent in the presence of FeCl3. The method permits efficient synthesis of structurally diverse 4-trans-alkoxycyclohexylamines. [Copyright &y& Elsevier]

Abstract: The treatment of 8,9,10-trimethoxy-7H-pyrrolo[3,2,1-de]phenanthridine-4,5-dicarboxylic acid with phenyliodine diacetate and potassium iodide in tetrahydrofuran gave the corresponding 4,5-diiodo derivative, which was converted to kalbretorine via reduction, demethylation, followed by alkylation. [Copyright &y& Elsevier]

Abstract: The total synthesis of Resolvin E2, an endogenous lipid mediator of the resolution of inflammation derived from eicosapentaenoic acid, has been achieved. The chiral hydroxy-groups at C5 and C18 were generated in a simple, efficient, and environmentally friendly manner via an asymmetric Noyori transfer hydrogenation in water using sodium formate as a reducing agent. Pd0/CuI Sonogashira couplings of the three key fragments and Zn(Cu/Ag) reduction completed the synthesis of Resolvin E2. [Copyright &y& Elsevier]

Abstract: The formation of alkoxy substituted di(pyridin-2-yl)amines and N-arylpyridin-2-ylamines by nitro group reduction is described. Unexpected substitution of ortho with the amino at C-6 was observed during the reduction using SnCl2·2H2O in different alcohols. The influence of the nature of the atom at the 3- and 5-positions of nitro-substituted di(pyridin-2-yl)amines and N-arylpyridin-2-ylamines was investigated. [Copyright &y& Elsevier]

Abstract: A mild and efficient synthetic route to the iboga scaffold by employing reductive-Heck type annulation is described. The utility of this process is demonstrated by the direct access to the ibogamine, epiibogamine and iboga-analogs. The cyclization precursors were readily obtained from 2-iodoaniline by heteroannulation reaction with suitable alkynes followed by iodination. [Copyright &y& Elsevier]

Abstract: The copper(II) complex [Cu(C186tren)](Br)2, 2, is an efficient precatalyst for the Huisgen ‘click’ cycloaddtion which can be used at low loading without the requirement of an external sacrificial reductant such as sodium ascorbate. EPR studies support the in situ reduction of 2 by the alkyne to generate a reactive copper(I) catalyst. [Copyright &y& Elsevier]

Abstract: The reaction of Artemisinin with solvated electrons () generated by radiolytic methods led to the formation of acid 2 as the only detectable product. A possible mechanism leading to the formation of compound 2 is discussed. [Copyright &y& Elsevier]

Abstract: The first enantiocontrolled total synthesis of heliespirone B has been accomplished employing a biomimetic intramolecular oxy-Michael reaction followed by the regio- and diastereoselective reduction of the carbonyl function as key steps. [Copyright &y& Elsevier]

Abstract: Protected 1,2,3-triols were prepared by organocatalytic α-hydroxylation of β-hydroxyaldehydes followed by in situ reduction. All diastereoisomers were obtained with correct yields and good to excellent de. The absolute configurations of the new asymmetric centers were confirmed by derivatization into the corresponding epoxide. [Copyright &y& Elsevier]

Abstract: A simple and efficient synthesis of indanones, bearing a quaternary carbon centre, has been developed. The method features, in a one-pot process, the use of a multi-task palladium catalyst for the sequential Heck-reduction reactions, followed by a base-mediated cyclization–alkylation sequence. This methodology, called Heck-reduction–cyclization–alkylation (HRCA), is carried out under mild and simple experimental conditions with the use of inexpensive reagents. The mild conditions have been made possible by the use of diazonium salts that allow Heck couplings at moderate temperature (40°C) under ligand-free conditions. [Copyright &y& Elsevier]

Abstract: Various selenyl-substituted aryl aldehydes were obtained using dithiothreitol (DTT) as a reducing agent for diselenides in the presence of a base. For electron-deficient haloaryl aldehydes, a weak base, such as K2CO3, performed well. However, for electron-rich haloaryl aldehydes, a stronger base, such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), was required for successful substitution. The selenyl-substitution of heteroaryl substrates were also investigated to obtain satisfactory yields of the desired products. [Copyright &y& Elsevier]

Abstract: The reductive coupling of 1,3-dimethyluracil with benzophenone by Zn–TiCl4 in THF gave unusual two-to-one adduct and its further reduced product. The reductive coupling of 1,3-dimethyl-5-fluorouracil with benzophenone by Zn–TiCl4 also gave two-to-one adduct. 1,3-Dimethylthymine was, however, completely inert under the same conditions. [Copyright &y& Elsevier]

Abstract: The synthesis of 2-(arylaminomethyl)phenylboronic acid via an amination–reduction reaction has been investigated within a model system comprising 2-formylphenylboronic acid and N-ethylaniline. Adoption of the appropriate reaction conditions influences the reactivity of 2-formylphenylboronic acid, enabling efficient synthesis of so-far unobtainable 2-(arylaminomethyl)phenylboronic compounds. The first crystal structure of the aromatic amine derivative has been determined and described. [Copyright &y& Elsevier]

Abstract: Bredinin (4-carbamoyl-1-β-d-ribofuranosylimidazolium-5-olate, 1) was synthesised by the formation of a malonamate from 2,3-isopropylidene-d-ribofuranosylamine and ethyl malonyl chloride, followed by a sequence involving amination, via reduction of an oxime, heterocycle formation and then deprotection. [Copyright &y& Elsevier]

Abstract: A 13-step, highly stereoselective synthesis of (−)-nakadomarin A has been achieved using the combination of a bifunctional organocatalyst controlled Michael addition, a nitro-Mannich/lactamization cascade, an alkyne ring-closing metathesis/syn-reduction, and furan/iminium ion cyclization/reduction as key steps. [Copyright &y& Elsevier]

Abstract: In the presence of silica gel or titanium tetrachloride, ketene silyl acetals or ketene silyl thioacetals underwent 1,4-addition with α,β unsaturated aldimines which possess a large triphenylmethyl group at the imino nitrogens followed by reduction with sodium cyanoborohydride to give aminopropylated products, δ-amino esters, in good yields. [Copyright &y& Elsevier]

Abstract: Conjugate reduction of ortho-substituted cinnamic esters by Stryker’s reagent to form copper enolates, followed by intramolecular aldol-type cyclization, successfully generated indane and tetralin rings in one pot efficiently. This tandem reaction is generally diastereoselective and provides good yields. [Copyright &y& Elsevier]

Abstract: The convergent syntheses of two possible diastereomers of the C25–C40 subunit resident in (−)-caylobolide A have been accomplished. The key reaction featured a chemoselective Ru-catalyzed cross-metathesis between a fully elaborated type I and two functionalized type II α,β-unsaturated ketones. [Copyright &y& Elsevier]

Abstract: Secondary amides undergo in situ silyl imidate formation mediated by TMSOTf and an amine base, followed by addition to acetal acceptors to provide N-acyl-N,O-acetals in good yields. An analogous, high-yielding reaction is observed with 2-mercaptothiazoline as the silyl imidate precursor. Competing reduction of the acetal to the corresponding methyl ether via transfer hydrogenation can be circumvented by the replacement of CY2NMe with 2,6-lutidine under otherwise identical reaction conditions. [Copyright &y& Elsevier]

Abstract: An asymmetric approach to key intermediate 17 starting from lactone 7 is described, in which Evan’s alkylation and CBS-catalyzed reduction are used for construction of the chiral centers, respectively. Thus, the synthesis of (E)-dehydroapratoxin A 6 could be accomplished in a general fashion, therein FDPP has been proven as an efficient condensation reagent for the coupling of amine 25 and carboxylic acid 24. [Copyright &y& Elsevier]

Abstract: We have developed a new method to synthesize aziridines from their corresponding hydantoins in one step using an excess of Red-Al overnight in refluxing toluene. This allows direct access to N–H aziridines without the need for protecting group strategies. [Copyright &y& Elsevier]

Abstract: A simple and useful method for the reduction of primary amides into the corresponding amines using a polymethylhydrosiloxane (PMHS)–Ti(OiPr)4 reducing system is described. Aromatic as well as aliphatic primary amides are reduced in high selectivity and excellent yields. The reduction could proceed via dehydration of the primary amide group into the corresponding nitrile which is then reduced into the corresponding primary amine. [Copyright &y& Elsevier]

Abstract: A library of benzimidazoles, benzoxazoles, and benzothiazoles was efficiently synthesized by condensation of o-phenylenediamine, o-aminophenol, and o-aminothiophenol respectively with aromatic aldehydes in the presence of catalytic amounts of Animal Bone Meal (ABM) and Lewis acids doped ABMs. Reactions were conducted under reflux conditions in air. The remarkable features of this new protocol are high conversion, short reaction times, and cleaner reaction profiles, straightforward procedure, and reduction in catalyst toxicity. [Copyright &y& Elsevier]

Abstract: An InBr3–Et3SiH reducing system was developed to selectively convert aliphatic ketones to a variety of secondary alcohols in moderate to good yields. An initial mixing of InBr3 and PhSiH3 was followed by the addition of aliphatic ketones and a solvent to afford the symmetrical ether derivatives. [Copyright &y& Elsevier]

Abstract: Vilsmeier–Haack formylation of 3,4-dimethoxypyrrole led to the unprecedented formation of 3-chloro-4-methoxypyrrole-2-aldehyde instead of the desired dialdehyde. Subsequent reduction and acid catalyzed cyclization led to the formation of type I, 3,8,13,18-tetrachloro-2,7,12,17-tetramethoxyporphyrin in approximately 6% yield. [Copyright &y& Elsevier]

Abstract: A ruthenium catalyst formed in situ by combining [Ru(p-cymene)Cl2]2 and an amino acid hydroxy-amide was found to catalyze efficiently the asymmetric reduction of aryl alkyl ketones under transfer hydrogenation conditions using ethanol as the hydrogen donor. The secondary alcohol products were obtained in moderate to good yields and with good to excellent enantioselectivity (up to 97% ee). [Copyright &y& Elsevier]

Abstract: The enantioselective total synthesis of Resolvin E1 (RvE1), a naturally occurring small molecule mediator of inflammation resolution, is reported. Two routes are presented, both modular and convergent in nature, with an excellent control of all stereocenters. The C12- and C18-hydroxy groups are derived from (S)-glycidol while the C5-hydroxy group is installed via enantioselective reduction of a ketone precursor. Both the cis-alkenes are introduced with excellent control by the reduction of a late-stage bis-alkyne intermediate. The synthetic disconnections are very amenable to analog preparation, and further modifications to the chemistry have allowed for scale-up and First in Man testing of this novel pro-resolution molecule. [Copyright &y& Elsevier]

Abstract: Palladium catalyzed simple and efficient protocol for reductive carbonylation of aryl and heteroaryl compounds has been developed. The formylation of aryl and heteroaryl iodides takes place in the presence of Pd(acac)2/dppm catalyst at 10bar pressure of synthetic gas to give the desired aromatic and heteroaromatic aldehydes in good to excellent yields. Easy work-up, stability of the catalyst, low catalyst loading and less reaction time are the advantages of this method. [Copyright &y& Elsevier]

Abstract: Regioselective titanium alkoxide-mediated reductive cross-coupling reactions of allylic alcohols with vinylsilanes and imines have previously been demonstrated to proceed with allylic transposition by formal metallo-[3,3]-rearrangement [thought to proceed by a sequence of: (1) directed carbometalation, and (2) syn-elimination]. While many examples have been described that support this reaction path, a collection of substrates have recently been identified that react by way of an alternative pathway, delivering a concise convergent route to coupled products bearing a quaternary center. [Copyright &y& Elsevier]

Abstract: A diversity generative approach to bioactive and structurally complex natural products paecilomycine A–C, involving an intramolecular Pauson–Khand reaction as a key step is delineated. [Copyright &y& Elsevier]

Abstract: ATH reductions of aliphatic ketones in water catalyzed by ruthenium coordinated by prolinamide ligands produce alcohols with moderate enantiomeric excesses in most cases. A set of seven aliphatic ketones is proposed for a rapid evaluation of the enantioselectivity of catalysts by one-pot multi-substrates reduction. The screening of a library of prolinamides shows that according to the structure of the ketones different ligands give the best asymmetric inductions. [Copyright &y& Elsevier]

Abstract: A simple, highly efficient, and economical biphasic cell-free system was developed for biocatalytic reduction of prochiral aromatic ketones to furnish enantiopure alcohols. This system is characterized by using endogenous enzymes of the cell-free extract to form enzyme-coupled NADPH recycling system. Besides, it offered much higher productivity than whole cells and greatly simplified the preparation process of biocatalysts in comparison with isolated enzymes. Various prochiral aromatic ketones, especially α-substituted acetophenone derivatives, were reduced to chiral alcohols with excellent enantiomeric excess (ee) and moderate to good yield by this cell-free system. [Copyright &y& Elsevier]

Abstract: Stereoselective synthesis of two distinctive pyranone skeletons diospongin A and cryptofolione has been described based on an asymmetric aldol reaction starting from Chan’s diene. The synthetic strategy involves the enantioselective Mukaiyama aldol, diastereoselective reduction of δ-hydroxy-β-keto ester, a tandem sequence of deprotection, and intramolecular oxa-Michael reaction to obtain diospongin A and an asymmetric allylation and lactone formation using ring-closing metathesis reaction to obtain cryptofolione. [Copyright &y& Elsevier]

Abstract: Quinine and quinidine were synthesized by a highly enantio- and stereoselective approach starting from a proline-catalyzed asymmetric cycloaldolization of benzyl bis(2-formylethyl)carbamate which gave a 70:30 mixture of (3R,4R)-N-Cbz-3-hydroxymethyl-4-hydroxypiperidine (96% ee) and its 4S-epimer (92% ee) in 94% yield after in situ NaBH4 reduction. [ABSTRACT FROM AUTHOR]

Abstract: Samarium(II) diiodide mediated intramolecular cyclisation of mixed enone–enoate substrates in THF/MeOH is described. Spirocyclic ethers are obtained, and the stereodefined preparation of 1-oxaspiro[4.4]nonan-7-one products is included. [ABSTRACT FROM AUTHOR]

Abstract: The reduction of allyl aryl ethers using sodium borohydride in the presence of a catalytic amount of ruthenium(III) chloride in various aqueous solvent mixtures at 0°C was examined. In aqueous tetrahydrofuran, hydrogenation was the favored pathway (85–100% yield of the corresponding aryl propyl ether); whereas in aqueous N-methylformamide, reductive cleavage predominated (4:1 mixture of phenolic product/aryl propyl ether). In order to gain some insight into the mechanism for this process, 3-octyn-1-ol and trans-2-decen-1-yl acetate were subjected to similar reductive conditions; and both substrates afforded products inconsistent with a single-electron-transfer mechanism. [ABSTRACT FROM AUTHOR]

Abstract: A rapid, economic, and high yielding methodology has been developed for hydroacylation/reduction of activated ketones by using 1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride as a catalyst in combination with triethylamine. The reaction proceeded at an ambient temperature via generating N-heterocyclic carbene in situ that interacted with the (hetero)aryl aldehyde employed. While the reduction of ketones takes place in MeOH, the hydroacylation process was found to be effective in THF for both electron rich and deficient aldehydes. [ABSTRACT FROM AUTHOR]

Abstract: A high-yielding and facile one-pot Leuckart-type reaction for rapid access to a number of 2° and 3° amines is described. [ABSTRACT FROM AUTHOR]

Abstract: The Heck–Matsuda arylation of 2-aza and 2-oxo-substituted acrylates is described. Several reaction conditions were evaluated including the influence of solvents, temperature, catalysts, and stoichiometry. While the oxygenated system was successfully arylated in benzonitrile with Pd2(dba)3 as catalyst, the aza-acrylate furnished methoxylated products. The methoxylated products were subjected to an elimination/reduction protocol to obtain the corresponding N,O-protected phenylalanine derivatives. A one-pot procedure for the preparation of phenylalanine derivatives from 2-aza-substituted acrylates is presented. [ABSTRACT FROM AUTHOR]

Abstract: Upon visible-light irradiation, reductive carboxylation of alkyl halides takes place by using a SmI2/Sm mixed system under atmospheric CO2 to afford the corresponding carboxylic acids in good to excellent yields. [Copyright &y& Elsevier]

Abstract: A facile and mild reduction procedure is reported for the preparation of chiral secondary alcohols prepared from α-substituted ketones using sodium borohydride and the chiral boronate ester (l)-TarB-NO2. Direct reduction of substituted ketones bearing Lewis basic heteroatoms generally provided secondary alcohols of only modest enantiomeric excess likely due to either competition between the target carbonyl and the functionalized sidechains at the Lewis acidic boron atom in TarB-NO2 or the added steric bulk of the α-sidechain. As an alternative method, these substrates were synthesized using TarB-NO2 via a two-step procedure involving the reduction of an α-halo ketone to a chiral terminal epoxide, followed by regioselective/regiospecific epoxide opening by various nucleophiles. This procedure provides access to a variety of functionalized secondary alcohols including β-hydroxy ethers, thioethers, nitriles, and amines with enantiomeric excesses of 94% and yields up to 98%. [Copyright &y& Elsevier]

Abstract: The first examples of highly selective deprotection of silyl ethers by DIBALH are reported. Its selectivity enabled us to remove a primary TBS group and a primary TBDPS group in the presence of a secondary TES group. [ABSTRACT FROM AUTHOR]

Abstract: The glycosylation of inactive glycosyl donors, such as methyl glycosides and 1-hydroxy sugars with nearly stoichiometric amounts of various alcohols (1.1equiv) in an ionic liquid containing a protic acid (acid-IL) under reduced pressure conditions proceeded effectively to give the corresponding glycosides in good to high yields. Furthermore, the acid-IL could be reused for additional glycosylations without the loss of efficiency. [ABSTRACT FROM AUTHOR]

Abstract: This work reports the catalytic activity of the oxo-complexes HReO4, MoO2(acac)2, WO2Cl2, and VO(acac)2 in the reduction of sulfoxides with PhSiH3 or HBcat. The results obtained showed that the catalyst systems PhSiH3/HReO4 (5mol%) and HBcat/HReO4 (5mol%) are highly efficient for the deoxygenation of sulfoxides. The complex MoO2(acac)2 was also efficient, but the reactions required more time and heating. Finally, the complexes WO2Cl2 and VO(acac)2 showed a moderate activity. [Copyright &y& Elsevier]

Abstract: Reduction of esters, amides, and ketones by N,N-diethylaniline borane is accelerated by catalysts derived from spiroborate complexes. Esters are reduced at ambient temperature in less than 4h with this amine borane and 5mol% spiroborate 6. Functional group selectivity shows ketone and tertiary amide reduction is faster than ester or nitrile reduction. [ABSTRACT FROM AUTHOR]

Abstract: Starting from a variety of substituted chroman-4-ones, a highly enantioselective CBS reduction using in situ-generated B–H catalyst gave (S)-chroman-4-ols. Azide inversion and reduction gave crude (R)-chroman-4-amines, which could be purified without chromatography by isolation as the (R)-mandelic or d-tartaric acid salts with good yields and excellent ee. [ABSTRACT FROM AUTHOR]