- A new amide from Zanthoxylum armatum
-
A new amide designated as armatamide (1) - along with two lignans, asarinin and fargesin, α- and β-amyrins, lupeol, and β-sitosterol-β-D- glucoside - has been isolated from the bark of Zanthoxylum armatum. The structure of the new compound was deduced by spectral and chemical analysis as N-(4'-methoxyphenyl ethyl)-3, 4-methylenedioxy cinnamoyl amide.
- Kalia, Narendra K.,Singh, Bikram,Sood, Ram P.
-
-
Read Online
- Reaction of Diisobutylaluminum Borohydride, a Binary Hydride, with Selected Organic Compounds Containing Representative Functional Groups
-
The binary hydride, diisobutylaluminum borohydride [(iBu)2AlBH4], synthesized from diisobutylaluminum hydride (DIBAL) and borane dimethyl sulfide (BMS) has shown great potential in reducing a variety of organic functional groups. This unique binary hydride, (iBu)2AlBH4, is readily synthesized, versatile, and simple to use. Aldehydes, ketones, esters, and epoxides are reduced very fast to the corresponding alcohols in essentially quantitative yields. This binary hydride can reduce tertiary amides rapidly to the corresponding amines at 25 °C in an efficient manner. Furthermore, nitriles are converted into the corresponding amines in essentially quantitative yields. These reactions occur under ambient conditions and are completed in an hour or less. The reduction products are isolated through a simple acid-base extraction and without the use of column chromatography. Further investigation showed that (iBu)2AlBH4 has the potential to be a selective hydride donor as shown through a series of competitive reactions. Similarities and differences between (iBu)2AlBH4, DIBAL, and BMS are discussed.
- Amberchan, Gabriella,Snelling, Rachel A.,Moya, Enrique,Landi, Madison,Lutz, Kyle,Gatihi, Roxanne,Singaram, Bakthan
-
supporting information
p. 6207 - 6227
(2021/05/06)
-
- A State-of-the-Art Heterogeneous Catalyst for Efficient and General Nitrile Hydrogenation
-
Cobalt-doped hybrid materials consisting of metal oxides and carbon derived from chitin were prepared, characterized and tested for industrially relevant nitrile hydrogenations. The optimal catalyst supported onto MgO showed, after pyrolysis at 700 °C, magnesium oxide nanocubes decorated with carbon-enveloped Co nanoparticles. This special structure allows for the selective hydrogenation of diverse and demanding nitriles to the corresponding primary amines under mild conditions (e.g. 70 °C, 20 bar H2). The advantage of this novel catalytic material is showcased for industrially important substrates, including adipodinitrile, picolinonitrile, and fatty acid nitriles. Notably, the developed system outperformed all other tested commercial catalysts, for example, Raney Nickel and even noble-metal-based systems in these transformations.
- Formenti, Dario,Mocci, Rita,Atia, Hanan,Dastgir, Sarim,Anwar, Muhammad,Bachmann, Stephan,Scalone, Michelangelo,Junge, Kathrin,Beller, Matthias
-
supporting information
p. 15589 - 15595
(2020/10/02)
-
- Deacetylative Amination of Acetyl Arenes and Alkanes with C-C Bond Cleavage
-
The Br?nsted acid-catalyzed synthesis of primary amines from acetyl arenes and alkanes with C-C bond cleavage is described. Although the conversion from an acetyl group to amine has traditionally required multiple steps, the method described herein, which uses an oxime reagent as an amino group source, achieves the transformation directly via domino transoximation/Beckmann rearrangement/Pinner reaction. The method was also applied to the synthesis of γ-aminobutyric acids, such as baclophen and rolipram.
- Hyodo, Kengo,Hasegawa, Genna,Maki, Hiroya,Uchida, Kingo
-
supporting information
p. 2818 - 2822
(2019/04/25)
-
- Combined Photoredox/Enzymatic C?H Benzylic Hydroxylations
-
Chemical transformations that install heteroatoms into C?H bonds are of significant interest because they streamline the construction of value-added small molecules. Direct C?H oxyfunctionalization, or the one step conversion of a C?H bond to a C?O bond, could be a highly enabling transformation due to the prevalence of the resulting enantioenriched alcohols in pharmaceuticals and natural products,. Here we report a single-flask photoredox/enzymatic process for direct C?H hydroxylation that proceeds with broad reactivity, chemoselectivity and enantioselectivity. This unified strategy advances general photoredox and enzymatic catalysis synergy and enables chemoenzymatic processes for powerful and selective oxidative transformations.
- Betori, Rick C.,May, Catherine M.,Scheidt, Karl A.
-
p. 16490 - 16494
(2019/11/03)
-
- Ruthenium(II)-cored supramolecular organic framework-mediated recyclable visible light photoreduction of azides to amines and cascade formation of lactams
-
Ru(bpy)3]2+-cored supramolecular organic framework SMOF-1, assembled from a [Ru(bpy)3]2+-derived hexaarmed molecule and cucurbit[8]uril, has been demonstrated to heterogeneously catalyze visible light-induced reduction of phenyl, benzyl, 2-phenylethyl and 3-phenylpropyl azides in acetonitrile to produce the corresponding amines in good to high yields. For the last two kinds of azides that bear a CO2Me group at the para-position of the benzene ring, cascade reactions take place to generate the corresponding lactams in high yields. Compared with homogeneous control [Ru(bpy)3]Cl2, SMOF-1 exhibits remarkably increased photocatalysis activity as a result of synergistic effect of the [Ru(bpy)3]2+ units that form cubic cages to host the azide molecules and related intermediates. Moreover, SMOF-1 displays high recyclability and considerable photocatalysis activity after 3 to 12 runs.
- Wu, Yi-Peng,Yan, Meng,Gao, Zhong-Zheng,Hou, Jun-Li,Wang, Hui,Zhang, Dan-Wei,Zhang, Junliang,Li, Zhan-Ting
-
p. 1383 - 1386
(2019/05/06)
-
- Method for preparing substituted primary aliphatic amine
-
The invention belongs to the fields of medicinal and natural compound chemical intermediates and related chemical technologies, and relates to a preparation method of substituted primary amine. The method adopts benzonitrile and its derivative as raw materials, takes nanoporous palladium as a catalyst, takes hydrogen as a hydrogen source, and performs selective hydrogenation to prepare the substituted primary amine. The molar concentration of benzonitrile and its derivative in a solvent is 0.01-2 mmol/mL, and the molar ratio of benzonitrile and its derivative to the catalyst is 1:0.01-1:0.5; the size pore skeleton of the nanoporous palladium is 1 nm to 50 nm; and the pressure of hydrogen gas is 0.1 to 20.0 MPa. The method has the beneficial effects that the obtained product has high selectivity, the reaction condition is very mild, no additives is needed, the operation and the post-treatment are simple, the catalyst reproducibility is good, the multi-time catalytic effect with repeateduse is not significantly reduced, and the method provides possibility for industrialization.
- -
-
Paragraph 0048-0055
(2019/01/21)
-
- Facile synthesis of supported Ru-Triphos catalysts for continuous flow application in selective nitrile reduction
-
The selective catalytic hydrogenation of nitriles represents an important but challenging transformation for many homogeneous and heterogeneous catalysts. Herein, we report the efficient and modular solid-phase synthesis of immobilized Triphos-type ligands in very high yields, involving only minimal work-up procedures. The corresponding supported ruthenium-Triphos catalysts are tested in the hydrogenation of various nitriles. Under mild conditions and without the requirement of additives, the tunable supported catalyst library provides selective access to both primary amines and secondary imines. Moreover, the first application of a Triphos-type catalyst in a continuous flow process is presented demonstrating high catalyst life-time over at least 195 hours without significant activity loss.
- Konrath, Robert,Heutz, Frank J.L.,Steinfeldt, Norbert,Rockstroh, Nils,Kamer, Paul C.J.
-
p. 8195 - 8201
(2019/09/19)
-
- Synthesis of cobalt nanoparticles by pyrolysis of Vitamin B12: A non-noble-metal catalyst for efficient hydrogenation of nitriles
-
A facile preparation of vitamin B12-derived carbonaceous cobalt particles supported on ceria is reported. The resulting composite material is obtained upon wet impregnation of ceria with natural cyanocobalamin and consecutive pyrolysis under inert conditions. The novel catalyst shows good to excellent performance in the industrially relevant heterogeneous hydrogenation of nitriles to the corresponding primary amines.
- Ferraccioli, Raffaella,Borovika, Diana,Surkus, Annette-Enrica,Kreyenschulte, Carsten,Topf, Christoph,Beller, Matthias
-
p. 499 - 507
(2018/02/07)
-
- Biocatalytic Formal Anti-Markovnikov Hydroamination and Hydration of Aryl Alkenes
-
Biocatalytic anti-Markovnikov alkene hydroamination and hydration were achieved based on two concepts involving enzyme cascades: epoxidation-isomerization-amination for hydroamination and epoxidation-isomerization-reduction for hydration. An Escherichia coli strain coexpressing styrene monooxygenase (SMO), styrene oxide isomerase (SOI), ω-transaminase (CvTA), and alanine dehydrogenase (AlaDH) catalyzed the hydroamination of 12 aryl alkenes to give the corresponding valuable terminal amines in high conversion (many ≥86%) and exclusive anti-Markovnikov selectivity (>99:1). Another E. coli strain coexpressing SMO, SOI, and phenylacetaldehyde reductase (PAR) catalyzed the hydration of 12 aryl alkenes to the corresponding useful terminal alcohols in high conversion (many ≥80%) and very high anti-Markovnikov selectivity (>99:1). Importantly, SOI was discovered for stereoselective isomerization of a chiral epoxide to a chiral aldehyde, providing some insights on enzymatic epoxide rearrangement. Harnessing this stereoselective rearrangement, highly enantioselective anti-Markovnikov hydroamination and hydration were demonstrated to convert α-methylstyrene to the corresponding (S)-amine and (S)-alcohol in 84-81% conversion with 97-92% ee, respectively. The biocatalytic anti-Markovnikov hydroamination and hydration of alkenes, utilizing cheap and nontoxic chemicals (O2, NH3, and glucose) and cells, provide an environmentally friendly, highly selective, and high-yielding synthesis of terminal amines and alcohols.
- Wu, Shuke,Liu, Ji,Li, Zhi
-
p. 5225 - 5233
(2017/08/17)
-
- Reduction of selenoamides to amines using SmI2-H2O
-
Selenoamides are selectively reduced to amines by SmI2 with H2O. The process is general for primary, secondary, and tertiary aryl and alkyl selenoamide substrates and selectively delivers amine products. The reduction proceeds under mild conditions using SmI2 activated by straightforward addition of H2O, and does not require an additional Lewis base additive.
- Thurow, Samuel,Lenardo, Eder J.,Just-Baringo, Xavier,Procter, David J.
-
supporting information
p. 50 - 53
(2017/11/28)
-
- Selective Hydrogenation of Nitriles to Primary Amines by using a Cobalt Phosphine Catalyst
-
A general procedure for the catalytic hydrogenation of nitriles to primary amines by using a non-noble metal-based system is presented. Co(acac)3 in combination with tris[2-(dicyclohexylphosphino)ethyl]phosphine efficiently catalyzes the selective hydrogenation of a wide range of (hetero)aromatic and aliphatic nitriles to give the corresponding amines.
- Adam, Rosa,Bheeter, Charles Beromeo,Cabrero-Antonino, Jose R.,Junge, Kathrin,Jackstell, Ralf,Beller, Matthias
-
p. 842 - 846
(2017/03/17)
-
- NNP-Type Pincer Imidazolylphosphine Ruthenium Complexes: Efficient Base-Free Hydrogenation of Aromatic and Aliphatic Nitriles under Mild Conditions
-
A series of seven novel NImNHP-type pincer imidazolylphosphine ruthenium complexes has been synthesized and fully characterized. The use of hydrogenation of benzonitrile as a benchmark test identified [RuHCl(CO)(NImNHPtBu)] as the most active catalyst. With its stable Ru-BH4 analogue, in which chloride is replaced by BH4, a broad range of (hetero)aromatic and aliphatic nitriles, including industrially interesting adiponitrile, has been hydrogenated under mild and base-free conditions.
- Adam, Rosa,Alberico, Elisabetta,Baumann, Wolfgang,Drexler, Hans-Joachim,Jackstell, Ralf,Junge, Henrik,Beller, Matthias
-
p. 4991 - 5002
(2016/04/05)
-
- Photochemical Formation and Cleavage of C-N Bond
-
A new photochemical method of C-N bond formation has been developed. A properly substituted trityl alcohol can cleave the benzylic C-O bond and replace it with a C-N bond which is stable under the irradiation conditions. The C-N bond can then be photochemically cleaved with the same light source when the nitrogen is protonated. (Chemical Presented).
- Wang, Pengfei,Lu, Wenya,Devalankar, Dattatray,Ding, Zhenying
-
supporting information
p. 170 - 172
(2015/07/28)
-
- Preparation and characterization of primary amines by potassium borohydride-copper chloride system from nitriles
-
Nitriles undergo reduction to primary amines under optimized conditions at 50 °C using 0.25 equiv of copper chloride and 3.0 equiv of potassium borohydride in 80 % isopropanol. The aromatic and aralkyl nitriles could be effectively reduced in yield ranging from 60 to 90 %.
- Jiang, Han,Hu, Jialei,Xu, Xinliang,Zhou, Yifeng
-
p. 3564 - 3566
(2015/12/30)
-
- Synthesis and antioxidant characteristic of novel thiazolidinone derivatives
-
A series of novel thiazolidinone derivatives have been synthesized by solventless condensation of N-alkylamines with arylaldehydes at room temperature followed by a microwave assisted solventless addition of thioglycollic acid to the resultant imines. The synthesized compounds are characterized by 1H NMR, 13C NMR, MS and X-ray techniques and one of the synthesized thiazolidinones has been evaluated for its antioxidant property.
- Amutha, Chinnadurai,Saravanan, Sivaperuman,Muthusubramanian, Shanmugam
-
p. 377 - 383
(2014/05/06)
-
- Directed lithiation of N′-[2-(4-methoxyphenyl)ethyl]-N, N-dimethylurea and tert-butyl [2-(4-methoxyphenyl)ethyl]carbamate
-
N′-[2-(4-Methoxyphenyl)ethyl]-N,N-dimethylurea and tert-butyl [2-(4-methoxyphenyl)ethyl]carbamate are doubly lithiated on the nitrogen and ortho to the directing metalating group at -20 to 0 °C with three mole equivalents of n-BuLi in anhydrous THF. Reactions of the dilithium reagents produced in situ with various electrophiles give high yields of the corresponding substituted products. In the case of the urea, side-products due to lithiation and substitution on one of the methyl groups of the urea unit are obtained in low yields (0-17%). Georg Thieme Verlag KG Stuttgart · New York.
- Smith, Keith,El-Hiti, Gamal A.,Alshammari, Mohammed B.
-
p. 394 - 402
(2014/02/14)
-
- Fe3O4-SiO2-P4VP pH-sensitive microgel for immobilization of nickel nanoparticles: An efficient heterogeneous catalyst for nitrile reduction in water
-
Fe3O4 magnetic nanoparticles (MNPs) were modified with (3-aminopropyl)triethoxysilane through silanization. An atom transfer radical polymerization-initiating site immobilized onto amine-functionalized Fe3O4 MNPs. The surface-initiated atom transfer radical polymerization of 4-vinylpyridine was then performed in the presence of Fe 3O4-SiO2-Br nanoparticles, which led to the formation of Fe3O4-SiO2-P4VP [P4VP=poly(4-vinylpyridine)] hybrid microgels cross-linked with Fe 3O4 MNPs. Our approach uses polymer microgels as templates for the synthesis of nickel nanoparticles (NiNPs). The tunable properties of synthesized NiNPs@Fe3O4-SiO2-P4VP pH-sensitive microgels were used in the catalytic reduction of aliphatic and aromatic nitriles. Moreover, the catalytic activity of metal nanocomposites that can be modulated by the volume transition of microgel structures with changing pH has been evaluated. TEM, X-ray photoelectron spectroscopy, thermogravimetric analysis, atomic absorption spectroscopy, XRD, UV/Vis spectroscopy, and FTIR spectroscopy were used to characterize the resultant catalyst. Mystery solved: Our approach uses polymer microgels as templates for the synthesis of nickel nanoparticles. The tunable properties of synthesized NiNPs@Fe3O 4-SiO2-P4VP [NiNPs=nickel nanoparticles; P4VP=poly(4-vinylpyridine)] pH-sensitive microgels are used in the catalytic reduction of aliphatic and aromatic nitriles. Moreover, the catalytic activity of metal nanocomposites that can be modulated by the volume transition of microgel structures with changing pH has been evaluated. Copyright
- Nabid, Mohammad Reza,Bide, Yasamin,Niknezhad, Mahvash
-
p. 538 - 546
(2014/03/21)
-
- Electron transfer reduction of nitriles using SmI2-Et 3N-H2O: Synthetic utility and mechanism
-
The first general reduction of nitriles to primary amines under single electron transfer conditions is demonstrated using SmI2 (Kagan's reagent) activated with Lewis bases. The reaction features excellent functional group tolerance and represents an attractive alternative to the use of pyrophoric alkali metal hydrides. Notably, the electron transfer from Sm(II) to CN functional groups generates imidoyl-type radicals from bench stable nitrile precursors.
- Szostak, Michal,Sautier, Brice,Spain, Malcolm,Procter, David J.
-
supporting information
p. 1092 - 1095
(2014/03/21)
-
- Reaction of InCl3 with various reducing agents: InCl 3-NaBH4-mediated reduction of aromatic and aliphatic nitriles to primary amines
-
While alternative methods of preparing dichloroindium hydride (HInCl 2) via the in situ reduction of InCl3 using lithium amino borohydride (LAB) were explored, generation of HInCl2 from the reduction of InCl3 by sodium borohydride (NaBH4) was also re-evaluated for comparison. The reductive capability of the InCl 3/NaBH4 system was found to be highly dependent on the solvent used. Investigation by 11B NMR spectroscopic analyses indicated that the reaction of InCl3 with NaBH4 in THF generates HInCl2 along with borane-tetrahydrofuran (BH 3?THF) in situ. Nitriles underwent reduction to primary amines under optimized conditions at 25 °C using 1 equiv of anhydrous InCl 3 with 3 equiv of NaBH4 in THF. A variety of aromatic, heteroaromatic, and aliphatic nitriles were reduced to their corresponding primary amine in 70-99% isolated yields. Alkyl halide and nitrile functional groups were reduced in tandem by utilizing the reductive capabilities of both HInCl2 and BH3?THF in a one-pot reaction. Finally, the selective reduction of the carbon bromine bond in the presence of nitriles was achieved by generating HInCl2 via the reduction InCl3 with NaBH4 in CH3CN or with lithium dimethylaminoborohydride (MeLAB) in THF.
- Saavedra, Jaime Z.,Resendez, Angel,Rovira, Alexander,Eagon, Scott,Haddenham, Dustin,Singaram, Bakthan
-
experimental part
p. 221 - 228
(2012/02/05)
-
- An improved and impurity-free large-scale synthesis of venlafaxine hydrochloride
-
An improved and impurity-free synthetic method for large-scale synthesis of venlafaxine hydrochloride was developed using inexpensive reagents. The overall yield obtained from this newly developed process is 55% in a highly pure state with >99.9% purity by HPLC.
- Saravanan, Mohanarangam,Satyanarayana, Bollikonda,Reddy, Padi Pratap
-
p. 1392 - 1395
(2012/01/13)
-
- Mild approach to the deprotection of Troc from protected amines using mischmetal and TMSCl
-
The 2,2,2-trichloroethoxycarbonyl (Troc) protecting group was efficiently removed from Troc-protected aliphatic and aromatic amines and also some Troc, Tos- and Troc, Ac-protected amines using activated mischmetal (MM). All reactions were performed by ref
- Vellemaee, Eerold,Stepanov, Vladimir,Maeorg, Uno
-
experimental part
p. 3397 - 3404
(2011/01/04)
-
- The use of immobilized crown ethers as in-situ N-protecting groups in organic synthesis and their application under continuous flow
-
In addition to their high affinity for inorganic cations, crown ethers have been shown to efficiently sequester ammonium ions, forming a stable adduct via hydrogen bonding. Using this principle, several authors have reported the use of crown ethers as protecting groups for amines however to date, their widespread use has been somewhat precluded by the difficulties associated with removal of the crown ether from the resulting reaction mixture. In order to address this problem, we report the preparation of an immobilized 18-crown-6 ether derivative and its incorporation into a flow reactor, demonstrating the ability to use and recycle the reagent for the chemoselective O-acylation and alkylation of bifunctional compounds such as 4-(2-aminoethyl)phenol and 4-nitrophenol.
- Wild, Gareth. P.,Wiles, Charlotte,Watts, Paul,Haswell, Stephen J.
-
supporting information; experimental part
p. 1618 - 1629
(2009/05/26)
-
- A highly active heterogeneous palladium catalyst supported on a synthetic adsorbent
-
A method to prepare heterogeneous palladium catalyst highly dispersed in a synthetic adsorbent DIAION HP20, has been demonstrated. Heterogeneous palladium catalyst are suitable for organic synthetic chemistry due to their high air-stability, reconverability, reusability, and non-residual property. The catalyst was obtained by adding DIAION HP20 into a rust-colored solution of Pd(OAc)2 in MeOH at room temperature. The resulting products was collected by filtration, washed with H2O and MeOH, and dried in vacuo to give a palladium-DIAION HP20 complex as a grey powder. The products was made from a physical interaction between the orbitals of the palladium species and π-electrons of the benzene rings of the adsorbents. The thermogravimetry- differential thermal analysis of the complex showed that the complex has no volatiles.
- Monguchi, Yasunari,Fujita, Yuki,Endo, Koichi,Takao, Shinobu,Yoshimura, Masatoshi,Takagi, Yukio,Maegawa, Tomohiro,Sajiki, Hironao
-
scheme or table
p. 834 - 837
(2009/06/25)
-
- Potent and selective adenosine A2A receptor antagonists: 1,2,4-Triazolo[1,5-c]pyrimidines
-
Antagonism of the adenosine A2a receptor offers great promise in the treatment of Parkinson's disease. In the course of exploring pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine A2A antagonists, which led to clinical candidate SCH 420814, we prepared 1,2,4-triazolo[1,5-c]pyrimidines with potent and selective (vs A1) A2a antagonist activity, including oral activity in the rat haloperidol-induced catalepsy model. Structure-activity relationships and plasma levels are described for this series.
- Neustadt, Bernard R.,Liu, Hong,Hao, Jinsong,Greenlee, William J.,Stamford, Andrew W.,Foster, Carolyn,Arik, Leyla,Lachowicz, Jean,Zhang, Hongtao,Bertorelli, Rosalia,Fredduzzi, Silva,Varty, Geoffrey,Cohen-Williams, Mary,Ng, Kwokei
-
scheme or table
p. 967 - 971
(2009/09/06)
-
- Reductions of aliphatic and aromatic nitriles to primary amines with diisopropylaminoborane
-
Diisopropylaminoborane [BH2Nf)Pr)2] in the presence of a catalytic amount of lithium borohydride (LiBH4) reduces a large variety of aliphatic and aromatic nitriles in excellent yields. BH 2NOPr)2 can be prepared by two methods: first by reacting diisopropylamineborane [(iPr)2N)BH3] with 1.1 equiv of n-butylhthium (n-BuLi) followed by methyl iodide (MeI), or reacting iPrN:BH 3 with 1 equiv of n-BuLi followed by trimethylsilyl chloride (TMSCl). BH2N(ZPr)2 prepared with MeI was found to reduce benzonitriles to the corresponding benzylamines at ambient temperatures, whereas diisopropylaminoborane prepared with TMSCl does not reduce nitriles unless a catalytic amount of a lithium ion source, such as LiBH4 or lithium tetraphenylborate (LiBPh4), is added to the reaction. The reductions of benzonitriles with one or more electron-withdrawing groups on the aromatic ring generally occur much faster with higher yields. For example, 2,4-dichlorobenzonitrile was successfully reduced to 2,4-dichlorobenzylamine in 99% yield after 5 h at 25 °C. On the other hand, benzonitriles containing electron-donating groups on the aromatic ring require refluxing in tetrahydrofuran (THF) for complete reduction. For instance, 4- methoxybenzonitrile was successfully reduced to 4-methoxybenzylamine in 80% yield. Aliphatic nitriles can also be reduced by the BH2N(iPr) 2/cat. LiBH4 reducing system. Benzyl cyanide was reduced to phenethylamine in 83% yield. BH2NOPr)2 can also reduce nitriles in the presence of unconjugated alkenes and alkynes such as the reduction of 2-hexynenitrile to hex-5-yn-l-amine in 80% yield. Unfortunately, selective reduction of a nitrile in the presence of an aldehyde is not possible as aldehydes are reduced along with the nitrile. However, selective reduction of the nitrile group at 25 °C in the presence of an ester is possible as long as the nitrile group is activated by an electron-withdrawing substituent. It should be pointed out that lithium aminoborohydrides (LABs) do not reduce nitriles under ambient conditions and behave as bases with aliphatic nitriles as well as nitriles containing acidic a-protons. Consequently, both LABs and BH2NOPr)2 are complementary to each other and offer methods for the selective reductions of multifunctional compounds.
- Haddenham, Dustin,Pasumansky, Lubov,DeSoto, Jamie,Eagon, Scott,Singaram, Bakthan
-
supporting information; experimental part
p. 1964 - 1970
(2009/07/01)
-
- (1-Nosyl-5-nitroindol-3-yl)methyl ester: A novel protective group for carboxylic acids
-
(Chemical Equation Presented) The usefulness of (1-nosyl-5-nitroindol-3-yl) methyl esters as a novel protective group for carboxylic acid is fully demonstrated. The novel protective group is stable under a broad range of conditions and can easily be deprotected under the mild conditions used for removal of the nosyl (Ns) group. It is orthogonal to the existing protective groups for carboxylic acids such as t-butyl and allyl esters.
- Nishimura, Takuya,Yamada, Kouhei,Takebe, Tohru,Yokoshima, Satoshi,Fukuyama, Tohru
-
supporting information; experimental part
p. 2601 - 2604
(2009/05/26)
-
- A mild method for cleavage of N-Tos protected amines using mischmetal and TiCl4
-
The para-toluenesulfonyl (Tos) protecting group is removed efficiently and quickly under neutral conditions from the corresponding protected primary and secondary amines using mischmetal in moderate to excellent yields.
- Vellem?e, Eerold,Lebedev, Oleg,M?eorg, Uno
-
p. 1373 - 1375
(2008/09/18)
-
- Instantaneous SmI2/H2O/amine mediated reduction of nitroalkanes and α,β-unsaturated nitroalkenes
-
A rapid method for efficient reduction of nitroalkanes and α,β-unsaturated nitroalkenes using SmI2/H2O/amine has been developed.
- Ankner, Tobias,Hilmersson, G?ran
-
p. 5707 - 5710
(2008/02/10)
-
- Design, synthesis, and structure-activity relationships of novel 2-substituted pyrazinoylguanidine epithelial sodium channel blockers: Drugs for cystic fibrosis and chronic bronchitis
-
Amiloride (1), the prototypical epithelial sodium channel (ENaC) blocker, has been administered with limited success as aerosol therapy for improving pulmonary function in patients with the genetic disorder cystic fibrosis. This study was conducted to synthesize and identify more potent, less reversible ENaC blockers, targeted for aerosol therapy and possessing minimal systemic renal activity. A series of novel 2-substituted acylguanidine analogues of amiloride were synthesized and evaluated for potency and reversibility on bronchial ENaC. All compounds tested were more potent and less reversible at blocking sodium-dependent short-circuit current than amiloride. Compounds 30-34 showed the greatest potency on ENaC with IC50 values below 10 nM. A regioselective difference in potency was found (compounds 30, 39, and 40), whereas no stereospecific (compounds 33, 34) difference in potency on ENaC was displayed. Lead compound 32 was 102-fold more potent and 5-fold less reversible than amiloríde and displayed the lowest IC50 value ever reported for an ENaC blocker.
- Hirsh, Andrew J.,Molino, Bruce F.,Zhang, Jianzhong,Astakhova, Nadezhda,Geiss, William B.,Sargent, Bruce J.,Swenson, Brian D.,Usyatinsky, Alexander,Wyle, Michael J.,Boucher, Richard C.,Smith, Rick T.,Zamurs, Andra,Johnson, M. Ross
-
p. 4098 - 4115
(2007/10/03)
-
- The facile preparation of primary and secondary amines via an improved Fukuyama-Mitsunobu procedure. Application to the synthesis of a lung-targeted gene delivery agent
-
An efficient modification of the Fukuyama-Mitsunobu procedure has been developed whereby primary or secondary amines can be synthesized from alkyl alcohols and the corresponding nosyl-protected/activated amine. Most importantly, the use of the DTBAD and diphenylpyridinylphosphine, as Mitsunobu reagents, generates reaction by-products that can be easily removed, providing a remarkably clean product mixture. This improved technique was implemented in the synthesis of a complex lipopeptide designed to target α 9β1-integrin proteins predominant on upper airway epithelial cells. The Royal Society of Chemistry 2005.
- Guisado, Cristina,Waterhouse, Jodie E.,Price, Wayne S.,Jorgensen, Michael R.,Miller, Andrew D.
-
p. 1049 - 1057
(2007/10/03)
-
- Dod-S-Me and methyl 6-morpholinohexyl sulfide (MMS) as new odorless borane carriers
-
Odorless Dod-S-Me (1) and MMS (3) are developed as efficient borane carriers. The yields of hydroborations and reductions with borane complex 2 of 1 are very high and the recovery of 1 after the reaction is quantitative. The borane complexes 4 and 5 of 3 are also useful. In the latter case chromatographic separation is unnecessary when excess oxidizing agent (alkaline H2O2) is used after hydroboration.
- Patra, Pranab K.,Nishide, Kiyoharu,Fuji, Kaoru,Node, Manabu
-
p. 1003 - 1006
(2007/10/03)
-
- 2-aminobenzoxazole derivatives and combinatorial libraries thereof
-
The present invention relates to novel 2-aminobenzoxazole derivative compounds of the following formula: wherein R1 to R4 and Z have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing 2-aminobenzoxazole derivative compounds.
- -
-
-
- 4-unsubstituted dihydroisoquinolinone derivatives and combinatorial libraries thereof
-
The present invention relates to novel dihydroisoquinolinone (DHQ) derivative compounds of the following formula: wherein R1to R7, X, Y, Z, b, c and d have the meanings provided herein. The invention further relates to combinatorial libraries containing two or more such compounds, as well as methods of preparing DHQ derivative compounds.
- -
-
-
- 5-HT2A receptor inverse agonists
-
Disclosed herein is a new class of pyrazole compounds which act at the 5HT2A receptors.
- -
-
-
- Small molecule modulators of non-endogenous, constitutively activated human serotonin receptors
-
Disclosed herein are non-endogenous, constitutively activated forms of the human 5-HT2A and human 5-HT2C receptors and uses of such receptors to screen candidate compounds. Further disclosed herein are candidate compounds identified by the screening method which act at the 5HT2A receptors. Yet further disclosed is a new class of compounds which act at the 5HT2A receptors.
- -
-
-
- Pictet-Spengler condensation of N-sulfonyl-β-phenethylamines with α- chloro-α-phenylselenoesters. New synthesis of 1,2,3,4- tetrahydroisoquinoline-1-carboxylates
-
The reaction of N-sulfonyl-β-phenethylamines with α-chloro-a- phenylseleno acetate/propionate esters under Lewis acid promotion gives moderate to good yields of the corresponding 1,2,3, 4- tetrahydroisoquinoline-1-carboxylates. Varying degrees of diastereoselection were obtained using chiral sulfonamides and/or esters. Employing this strategy, the achievement of a new total synthesis of Calycotomine is reported.
- Silveira, Claudio C.,Bernardi, Carmem R.,Braga, Antonio L.,Kaufman, Teodoro S.
-
p. 4969 - 4972
(2007/10/03)
-
- Unusually Long Lifetimes of the Singlet Derived from 4-Azido-2,3,5,6-tetrafluorobenzamides
-
Laser flash photolysis (308 nm, 20 ns, 150 mJ) of 4-azido-2,3,5,6-tetrafluorobenzamides, esters, and thioesters generate singlet nitrenes which can be intercepted with pyridine to produce strongly absorbing ylides.It was possible to resolve the rate of formation of the ylides as a function of pyridine concentration.This has lad to direct measurements of the absolute rate constants of (a) the reaction of the nitrene with pyridine, (b) ring expansion of the nitrene to a ketenimine, and (c) singlet to triplet nitrene intersystem crossing.
- Marcinek, Andrzej,Platz, Matthew S.,Chan, Stephen Y.,Floresca, Rey,Rajagopalan, Krishnan,et al.
-
p. 412 - 419
(2007/10/02)
-
- Process for the preparation of (8As,12AS,13AS)-decahydroisoquino ((2,1-G) (1,6)-naphthyridin-8-one derivatives
-
The invention provides a process for preparing single enantiomers of compounds represented by the formula: STR1 and chiral acid addition salts thereof; wherein: X and Y are independently hydrogen; lower alkyl; lower alkoxy; or halo; or X and Y taken together is methylenedioxy or ethylene-1,2-dioxy; which includes reduction of a compound represented by the formula: STR2 to give a mixture of stereoisomers represented by the formula: STR3 wherein each wavy line independently represents a bond in either the α or β position; followed by dissolving the mixture of stereoisomers and a chiral resolving acid in a suitable solvent and allowing the solution to crystallize, giving a salt of the desired enantiomer.
- -
-
-
- A Facile Approach to 2-Arylethylamines via Polymeric Palladium Catalyst
-
2-Arylethylamines were synthesized in moderate yields via Heck reaction of acrylamide with iodobenzenes in the presence of polymeric catalyst P-ph-phen.Pd(0) followed by hydrogenation and subsequent Hofmann reaction.
- Zhuangyu, Zhang,Yi, Pan,Hongwen, Hu,Tsi-yu, Kao
-
p. 3563 - 3574
(2007/10/02)
-
- Studies of Reduction with Dimethoxyborane-Transition Metal Salt Systems. I. Reduction of Nitriles, Aldehydes and Ketones with Dimethoxyborane-Transition Metal Salt Systems
-
The reduction of a variety of functional groups with new dimethoxyborane-transition metal salt systems was investigated.The dimethoxyborane-cobaltous chloride system reduced nitriles and aldehydes under mild conditions in good yields, and the dimethoxyborane-nickelous chloride system similarly reduced nitriles, aldehydes, olefin and ketones.The other functional groups tested were unaffected by these systems.Keywords reduction; nitrile; aldehyde; ketone; dimethoxyborane; transition metal salt; dimethoxyborane-cobaltous chloride system; dimethoxyborane-nickelous chloride system
- Nose, Atsuko,Kudo, Tadahiro
-
p. 808 - 810
(2007/10/02)
-
- PO-Activated Olefination and Conversion of Aldehydes and Ketones to Higher Amines; II. Synthesis of Arylethylamines
-
The transformation of arylcarboxaldehydes and/or - ketones 2 by three different routes into arylethylamines 3 and/or 4 is reported.According to the first route, the intermediate iminophosphonates 9 react through a classical PO-activated olefination.The second and the third involve the rearrangement of the iminophosphonates 9 into the vinylphosphoramidates 12.
- Heymes, A.,Chekroun, I.
-
p. 245 - 249
(2007/10/02)
-
- Nickel-Catalyzed Synthesis of Arylacetonitriles from Arylzinc Chlorides and Bromoacetonitrile
-
Arylacetonitriles are synthesised by coupling arylzinc chlorides with bromoacetonitrile using Ni(acac)2/P(c-C6H11)(C6H5)2 as catalyst.The arylacetonitriles are reduced in situ with LiAlH4/AlCl3 to give the corresponding 2-aryl-1-aminoethanes.
- Frejd, Torbjoern,Klingstedt, Tomas
-
-
- Inhibition of phenylethanolamine n-methyltransferase (PNMT) by aromatic hydroxy-substituted 1,2,3,4-tetrahydroisoquinolines: Further studies on the hydrophilic pocket of the aromatic ring binding region of the active site
-
In a continuation of studies directed toward characterizing the hydrophilic pocket within the aromatic ring binding region of the active site of phenylethanolamine N-methyltransferase (PNMT), 5-, 6-, 7-, and 8-hydroxy-1,2,3,4-tetrahydroisoquinoline were prepared and evaluated as substates and inhibitors of PNMT. In order to discern the necessity of an acidic hydrogen for interaction at this pocket the corresponding methyl ethers were also evaluated. The enhanced affinity of 7-hydroxy-1,2,3,4-tetrahydroisoquinoline (16) versus tetrahydroisoquinoline (13) itself indicates that a hydrophilic pocket exists off of carbon C7 in bound tetrahydroisoquinolines. The diminished affinity of the corresponding methyl ether is consistent with a requirement for the acidic hydrogen of 16 for interaction of the aromatic hydroxyl at site. From the relative activities of the other regioisomeric aromatic hydroxyl-substituted tetrahydroisoquinolines, their corresponding methyl ethers, and 6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, it appears that the hydrophilic pocket is spatially compact with respect to bound tetrahydroisoquinolines and is surrounded by larger areas of lipophilic character. To allow a comparison of the results of this study with previous data on bound β-phenylethylamines, the methyl ethers of 5-, 6-, 7-, and 8-hydroxy-exo-2-aminobenzonorbornene and of 5- and 6-hydroxy-anti-9-aminobenzonorbornene were also evaluated for their activity as substrates and inhibitors for PNMT. The results of this study are in agreement with previous findings for bound β-phenylethylamines and support the conclusion that the natural substrate for PNMT, norepinephrine, has a different active site binding orientation than most known substrates and competitive inhibitors of the enzyme.
- Sall,Grunewald
-
p. 2208 - 2216
(2007/10/02)
-
- Diazaestrones and analogs. I. Pharmacological study and synthesis of heterosteroid analogs to establish structure-analgesic activity relationships
-
With the intention of showing the effect, about pharmacological properties, in replacing two estron asymetric carbon by nitrogen atoms and removal of angular methyl from steroid, stereospecific synthesis of 8,13-diazaestron and several substituted similar compounds was realized from β-1-(succinimidoethyl)-dihydroisoquinolines, precursors of a C open ring synthesis. The splitting of the 2-methoxydiazaestron methyl ester was carried out by mean of binaphthylphosphoric acid, and synthesis of several modified analogs of heterosteroid, was carried out to determine the effect of aromatic ring reduction, lactamic carbonyl reduction, and distance between 8 and 13 nitrogen atoms, about pharmacological activity. Hormonal, spasmolytic and analgesic activities were studied, good results were observed in analgesic activity.
- Hocquaux,Marcot,Redeuilh,et al.
-
p. 319 - 329
(2007/10/02)
-