- Aluminum Metal-Organic Framework-Ligated Single-Site Nickel(II)-Hydride for Heterogeneous Chemoselective Catalysis
-
The development of chemoselective and heterogeneous earth-abundant metal catalysts is essential for environmentally friendly chemical synthesis. We report a highly efficient, chemoselective, and reusable single-site nickel(II) hydride catalyst based on robust and porous aluminum metal-organic frameworks (MOFs) (DUT-5) for hydrogenation of nitro and nitrile compounds to the corresponding amines and hydrogenolysis of aryl ethers under mild conditions. The nickel-hydride catalyst was prepared by the metalation of aluminum hydroxide secondary building units (SBUs) of DUT-5 having the formula of Al(μ2-OH)(bpdc) (bpdc = 4,4′-biphenyldicarboxylate) with NiBr2 followed by a reaction with NaEt3BH. DUT-5-NiH has a broad substrate scope with excellent functional group tolerance in the hydrogenation of aromatic and aliphatic nitro and nitrile compounds under 1 bar H2 and could be recycled and reused at least 10 times. By changing the reaction conditions of the hydrogenation of nitriles, symmetric or unsymmetric secondary amines were also afforded selectively. The experimental and computational studies suggested reversible nitrile coordination to nickel followed by 1,2-insertion of coordinated nitrile into the nickel-hydride bond occurring in the turnover-limiting step. In addition, DUT-5-NiH is also an active catalyst for chemoselective hydrogenolysis of carbon-oxygen bonds in aryl ethers to afford hydrocarbons under atmospheric hydrogen in the absence of any base, which is important for the generation of fuels from biomass. This work highlights the potential of MOF-based single-site earth-abundant metal catalysts for practical and eco-friendly production of chemical feedstocks and biofuels.
- Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Dwivedi, Ashutosh,Manna, Kuntal
-
p. 3943 - 3957
(2021/04/12)
-
- Synthesis and Cytotoxicity of Octahydroepoxyisoindole-7-carboxylic Acids and Norcantharidin–Amide Hybrids as Norcantharidin Analogues
-
Octahydroepoxyisoindole analogues of norcantharidin were accessed through a Diels–Alder reaction of an amine-substituted furan with maleic anhydride and subsequent reduction of the bicyclo[2.2.1]heptene olefin. Despite retention of the carboxylate and the ether bridgehead known to impart cytotoxic activity to norcantharidin, none of these analogues displayed notable cytotoxicity against the 11 cell lines examined: HT29 (colon), MCF-7 (breast), A2780 (ovarian), H460 (lung), A431 (skin), Du145 (prostate), BE2-C (neuroblastoma), SJ-G2 and U87 (glioblastoma), MIA (pancreatic), and SMA (spontaneous murine astrocytoma). The incorporation of an amino-substituted system post-synthesis of norcantharidin afforded facile access to 14 acid/amide-substituted norcantharidin analogues. Of these, only four displayed sufficient activity at the initial 25 μm compound screening dose to warrant full evaluation of growth inhibition. Common to these analogues was the presence of a 4-biphenyl moiety, and in particular 3-(2-(furan-2-ylmethyl)-3-(4-biphenylamino)-3-oxopropylcarbamoyl)-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid (13 c) and 3-(2-(pyrrole-2-ylmethyl)-3-(4-biphenylamino)-3-oxopropylcarbamoyl)-7-oxabicyclo[2.2.1]heptane-2-carboxylic acid (24) displayed high levels of cytotoxicity, returning GI50 values of 15 nm (HT29) to 2.9 μm (U87) and 17 nm (SMA) to 2.8 μm (U87), respectively. These are the most cytotoxic norcantharidin analogues reported to date.
- Hizartzidis, Lacey,Gilbert, Jayne,Gordon, Christopher P.,Sakoff, Jennette A.,McCluskey, Adam
-
p. 1152 - 1161
(2019/05/24)
-
- 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.
-
-
- Synthesis and spectral studies on Ni(II) complexes involving N-furfuryl-N-substituted benzyldithiocarbamates and PPh3: Anagostic and C–H…π(chelate) interactions in (N-furfuryl-N-(4-fluorobenzyl)dithiocarbamato-S,S′)(thiocyanato-N)(tr
-
Twelve new nickel(II) complexes of functionalized dithiocarabamates [Ni(S2CNRR?)2](1-6) and [Ni(S2CNRR?)(NCS)(PPh3)](7-12) [where R=furfuryl; R?=2-hydroxy benzyl (1,7), 3-hydroxy benzyl (2,8), 4-hydroxy benzyl (3,9), 4-methoxy benzyl
- Sathiyaraj,Thirumaran,Ciattini, Samuele
-
p. 1042 - 1050
(2016/07/06)
-
- Palladium meditated CPhenyl-H bond activation of 2-furylimines versus tert-2-furylbenzylamines
-
The reactions of 2-furylimines 2a-f and Na2PdCl4 in the presence of NaOAc at 8-10°C result in nitrogen-palladium coordinated complexes 3a-f. Reduction of 2d-f with NaBH4 followed by N-methylation leads to the corresponding tert-2-furylbenzylamines 5a-c. Treatment of 5a-c with Na2PdCl4 at the same reaction condition as mentioned above affords palladacycles 6a-c where the Pd atoms connect to the phenyl ring rather than the furyl ring. The fact that 5a-c are more active than 2d-f in CPhenyl-H bond activation implies that the electron density of C10 or C8 atom in former is higher than those in latter. Compounds 3a-f, 5a-c, 6a-c were identified by elemental analysis, IR and NMR. In addition, the structures of 3b, 3f and 6c were also confirmed by their single crystal X-ray diffractions.
- Hu, Zhao-Xia,Ma, Nan,Zhang, Jin-Hua,Hu, Wen-Ping,Wang, Hong-Xing
-
-
- Chemoselective flow hydrogenation approaches to isoindole-7-carboxylic acids and 7-oxa-bicyclio[2.2.1]heptanes
-
Two libraries of highly decorated norcantharidin analogues were accessed via a series of sequential chemoselective flow hydrogenations and solvent-free transformations. Utilising a 10% Pd/C catalyst, modifications to reaction parameters (H2 pressure, temperature and flow rate conditions) allowed facile access to effect selective direct reductive aminations and olefin reductions in the presence of furan, benzyl and nitrile moieties were established. The use of 20% Pd(OH)2/C; Pd tetrakis; 5% Pt/C (sulfided) gave mixtures of furan and olefin (both reduced) and olefin reduced products. RuO2; 0.5% Re/C and Re2O7 resulted in no reduction. Concurrent olefin and nitrile reduction was achieved in the presence of furan moieties by employing a RANEY nickel catalyst. In total, 31 reaction conditions were examined using less than 200 mg of reagents allowing optimised conditions to be efficiently determined. These optimised hydrogenation conditions afforded desired analogues in near quantitative yields thus removing the requirements of reaction workup and chromatography.
- Hizartzidis,Tarleton,Gordon,McCluskey
-
p. 9709 - 9722
(2014/03/21)
-
- Regioselective domino metathesis of 7-oxanorbornenes and its application to the synthesis of biologically active glutamate analogues
-
A highly regioselective domino metathesis reaction of 7-oxanorbornene was developed that employed an intramolecular association of an amide carbonyl group to a ruthenium metal centre. By using this reaction, twelve glutamate analogues inspired by dysiherbaine were efficiently synthesized over 12-14 steps; one of the analogues exhibited bioactivity consistent with central nervous system depression. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Ikoma, Minoru,Oikawa, Masato,Gill, Martin B.,Swanson, Geoffrey T.,Sakai, Ryuichi,Shimamoto, Keiko,Sasaki, Makoto
-
supporting information; experimental part
p. 5215 - 5220
(2009/07/19)
-
- Synthesis and domino metathesis of functionalized 7-oxanorbornene analogs?toward cis-fused heterocycles
-
Here, we report our strategy to synthesize structurally diverse cis-fused heterocycles via 7-oxanorbornene analogs. By the intramolecular Diels-Alder reaction of 3-iodoacrylamide, followed by the domino metathesis reaction, the cis-fused heterobicyclic sk
- Ikoma, Minoru,Oikawa, Masato,Sasaki, Makoto
-
p. 2740 - 2749
(2008/09/19)
-
- Intra-molecular Diels-Alder reactions of citraconamic acids from furfurylamines and citraconic anhydride: Effects of substitution in the furan ring on regioselectivity
-
Regioselectivity in the intra-molecular Diels-Alder (IMDA) reaction of furfurylcitraconamic acids derived from N-benzylfurfurylamines and citraconic anhydride can be controlled by substituents located in the furan ring and by reaction conditions. Reactions conducted under kinetic conditions resulted in cycloaddition products having methyl and aminomethylene substituent in 1,3-relationship whereas under thermodynamic conditions, excepting in the case of the 3-methylsulfanyl group, the products rearranged to more stable cycloadducts in which the substituents are in 1,2-relationship. Product formation can be explained on the basis of frontier orbital interactions and steric considerations.
- Murali, Rajappa,Surya Prakash Rao,Scheeren, Hans W
-
p. 3165 - 3174
(2007/10/03)
-
