- β-Borylation of conjugated carbonyl compounds with silylborane or bis(pinacolato)diboron catalyzed by Au nanoparticles
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Conjugated aldehydes and ketones undergo reaction with Me2PhSiBpin (pin: pinacolato) catalyzed by Au nanoparticles supported on TiO2 forming exclusively the β-borylation products, via the intermediate formation of the labile silaboration adducts. This chemoselectivity pathway is complementary to the so far known analogous reaction catalyzed by other metals, where β-silylation occurs instead. β-Borylation also occurs with pinBBpin under identical reaction conditions in a variety of conjugated carbonyl compounds, including esters and amides which are unreactive in their attempted Au-catalyzed silaboration. This journal is
- Fragkiadakis, Michael,Kidonakis, Marios,Stratakis, Manolis
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p. 8921 - 8927
(2020/11/23)
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- β-Boration of α,β-unsaturated carbonyl compounds in ethanol and methanol catalyzed by CCC-NHC pincer Rh complexes
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Quantitative β-boration of α,β-unsaturated carbonyl compounds was achieved utilizing the eco-friendly solvent EtOH along with MeOH at room temperature in 1 h, by a CCC-NHC pincer Rh complex mixture. Substrates with β-substituents were successfully convert
- Reilly, Sean W.,Akurathi, Gopalakrishna,Box, Hannah K.,Valle, Henry U.,Hollis, T. Keith,Webster, Charles Edwin
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- ?-boration of alkene and alkyne intermediates
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The present invention relates to the field of organic chemistry, and in particular to the preparation of β-borated compounds. These β-borated compounds can be used as intermediates in the synthesis of pharmaceutically active agents such as Sitagliptin.
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Paragraph 0092; 0093
(2013/10/22)
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- ?-BORATION OF ALKENE AND ALKYNE INTERMEDIATES
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The present invention relates to the field of organic chemistry, and in particular to the preparation of β-borated compounds. These β-borated compounds can be used as intermediates in the synthesis pharmaceutically active agents such as sitagliptin.
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Page/Page column 37
(2013/10/22)
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- ?-boration of alkene and alkyne intermediates
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The present invention relates to the field of organic chemistry, and in particular to the preparation of β-borated compounds. These β-boated compounds can be used as intermediates in the synthesis of pharmaceutically active agents such as Sitagliptin.
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Paragraph 0071
(2013/10/22)
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- Basic CuCO3/ligand as a new catalyst for 'on water' borylation of Michael acceptors, alkenes and alkynes: Application to the efficient asymmetric synthesis of β-alcohol type sitagliptin side chain
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The efficient 'on water' β-borylation using bis(pinacolato)diboron agent was achieved with a newly developed catalytic system based on basic copper carbonate and various ligands. The catalytic system was used for β-borylation of various Michael acceptors,
- Stavber, Gaj,Casar, Zdenko
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p. 159 - 165
(2013/05/09)
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- Activation of diboron reagents with bronsted bases and alcohols: An experimental and theoretical perspective of the organocatalytic boron conjugate addition reaction
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Bases play an important role in organocatalytic boron conjugate addition reactions. The sole use of MeOH and a base can efficiently transform acyclic and cyclic activated olefins into the corresponding β-borated products in the presence of diboron reagents. Inorganic and organic bases deprotonate MeOH in the presence of diboron reagents. It is concluded, on the basis of theoretical calculations, NMR spectroscopic data, and ESI-MS experiments, that the methoxide anion forms a Lewis acid-base adduct with the diboron reagent. The sp 2 B atom of the methoxide-diboron adduct gains a strongly nucleophilic character, and attacks the electron-deficient olefin. The methanol protonates the intermediate, generating the product and another methoxide anion. This appears to be the simplest method to activate diboron reagents and make them suitable for incorporation into target organic molecules. The simplest method to activate diboron reagents and make them suitable for incorporation in targeted organic molecules seems to be deprotonation of MeOH by base (e.g., Verkade's base) to generate the methoxide anion, which interacts with the diboron reagent to give a nucleophilic Lewis acid-base adduct that promotes the β-boration of α,β-unsaturated carbonyl substrates. Methanol protonates the intermediate to generate the product and another methoxide anion (see scheme). Copyright
- Pubill-Ulldemolins, Cristina,Bonet, Amadeu,Bo, Carles,Gulyas, Henrik,Fernandez, Elena
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supporting information; experimental part
p. 1121 - 1126
(2012/03/22)
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- Structure and reactivity of a preactivated sp2-sp3 diboron reagent: Catalytic regioselective boration of α,β-unsaturated conjugated compounds
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A novel sp2-sp3 diboron reagent has been developed for the copper-catalyzed β-boration of α,β-unsaturated conjugated compounds. The reaction proceeds under mild conditions with various substrates, i.e., α,β-unsaturated esters, ketones, nitriles, ynones, amides, and aldehydes, in the absence of additives such as phosphine and sodium tert-butoxide to provide β-borylhomoenolates in good to excellent yields. The presence of an sp3-hybridized boron center, unambigously confirmed by X-ray crystallography, sufficiently activates the unsymmetrical pinacolato diisopropanolaminato diboron (PDIPA diboron, 2) to transfer the sp2-hybridized boron moiety chemoselectively. These observations suggest that the activation of one of the boron atoms is an essential step in the Cu-catalyzed β-boration catalytic cycle.
- Gao, Ming,Thorpe, Steven B.,Kleeberg, Christian,Slebodnick, Carla,Marder, Todd B.,Santos, Webster L.
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experimental part
p. 3997 - 4007
(2011/06/27)
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- Tandem β-boration/arylation of α,β-unsaturated carbonyl compounds by using a single palladium complex to catalyse both steps
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Diphenyl(3-methyl-2-indolyl)phosphine (C9H8NPPh 2, 1) gives stable dimeric palladium(II) complexes that contain the phosphine in P,Nbridging coordination mode. On treating 1 with [Pd(O 2CCH3)2], the new complexes [Pd(μ-C 9H7NPPh2)-(NCCH3)]2 (2) or [Pd(μ-C9H7NPPh2)-(μ-O 2CCH3)]2 (3) were isolated, depending on the solvent used, acetonitrile or toluene, respectively. Further reaction of 3 with the ammonium salt of 1 led to the substitution of one carboxylate ligand to afford [Pd(u-C9H7NPPh2)3(μ-O 2CCH3)] (4), in which the bimetallic unit is bonded by three C9H7NPPh2- moieties and one carboxylate group. Using this methodology, [Pd2(μ-C 6H4PPh2)2(μ-C9H 7NPPh2)(μ-O2CCX3)] (X = H (7); J. = F (8)) were synthesised from the ortho-metalated compounds [Pd(C 6H4PPh2)(μO2CCX3)], (X = H (5); J. = F (6)). Complexes 3, 4, 7, and 8 have been found to be active in the catalytic β-boration of α,β-unsaturated esters and ketones under mild reaction conditions. Hindrance of the carbonyl moiety has an influence on the reaction rate, but quantitative conversion was achieved in many cases. More remarkably, when aryl bromides were added to the reaction media, complex 7 induced a highly successful consecutive β-boration/crosscoupling reaction with dimethyl acrylamide as the substrate (99% conversion, 89 % isolated yield).
- Bonet, Amadeu,Gulyas, Henrik,Koshevoy, Igor O.,Estevan, Francisco,Sanau, Mercedes,Ubeda, M. Angeles,Fernandez, Elena
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supporting information; scheme or table
p. 6382 - 6390
(2010/08/03)
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- Sp2 - Sp3 hybridized mixed diboron: Synthesis, characterization, and copper-catalyzed β-boration of α,β- unsaturated conjugated compounds
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A novel sp2 - sp3 hybridized mixed diboron and its reactivity on the copper-catalyzed β-boration of α,β-unsaturated conjugated compounds to afford the corresponding β-borated compounds is reported. The presence of sp3-hybr
- Gao, Ming,Thorpe, Steven B.,Santos, Webster L.
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supporting information; experimental part
p. 3478 - 3481
(2009/12/05)
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- Copper-Catalyzed conjugate addition of diboron reagents to α,β-unsaturated amides: Highly reactive copper-1,2- bis(diphenylphosphino)benzene catalyst system
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An efficient copper catalyst system for the β-boration of α,β-unsaturated amides has been developed. Copper-bisphosphine complexes with small bite angles generate efficient catalyst systems for the successful conjugate addition of bis(pinaco-lato)diboron
- Chea, Heesung,Sim, Hak-Suk,Yun, Jaesook
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supporting information; experimental part
p. 855 - 858
(2009/10/25)
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- Suzuki-Miyaura cross-coupling of potassium trifluoroboratohomoenolates
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Ketone-, ester-, and amide-containing potassium trifluoroboratohomoenolates were prepared in good to excellent yields from the corresponding unsaturated carbonyl compounds. They were shown to be effective coupling partners in the Suzuki-Miyaura reaction with a variety of electrophiles including electron-rich and electron-poor aryl bromides and -chlorides.
- Molander, Gary A.,Petrillo, Daniel E.
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supporting information; experimental part
p. 1795 - 1798
(2009/04/10)
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