- Synthesis of Spirobicyclic Pyrazoles by Intramolecular Dipolar Cycloadditions/[1s, 5s] Sigmatropic Rearrangements
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The formation of fused pyrazoles via intramolecular 1,3-dipolar cycloadditions of diazo intermediates with pendant alkynes is described. A subsequent thermal [1s, 5s] sigmatropic shift of these pyrazole systems resulted in a ring contraction, forming spirocyclic pyrazoles. The limitations of this rearrangement were explored by changing the substituents on the nonmigrating aromatic ring and by using substrates lacking an aromatic linkage to the propargyl group.
- Dimirjian, Christine A.,Casti?eira Reis, Marta,Balmond, Edward I.,Turman, Nolan C.,Rodriguez, Elys P.,Di Maso, Michael J.,Fettinger, James C.,Tantillo, Dean J.,Shaw, Jared T.
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supporting information
p. 7209 - 7212
(2019/10/02)
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- Enantioselective intramolecular C-H insertion reactions of donor-donor metal carbenoids
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The first asymmetric insertion reactions of donor-donor carbenoids, i.e., those with no pendant electron-withdrawing groups, are reported. This process enables the synthesis of densely substituted benzodihydrofurans with high levels of enantio- and diaste
- Soldi, Cristian,Lamb, Kellan N.,Squitieri, Richard A.,Gonzlez-Lpez, Marcos,Di Maso, Michael J.,Shaw, Jared T.
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supporting information
p. 15142 - 15145
(2015/02/19)
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- (Chiral) lithium-(magnesium-)zinc and lithium-cobalt combinations as dual reagents for aromatic deproto-metalation and aryl transfer to aldehydes
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The deprotonating ability of mixed lithium-zinc or lithium-magnesium-zinc combinations containing amido and alkyl ligands in tetrahydrofuran were compared using anisole as substrate and iodine to quantitatively trap the formed arylmetal species. The results showed that the deprotonating ability is hampered if a Grignard reagent is employed to introduce the alkyl ligand, and is reduced when 2,2,6,6-tetramethylpiperidino ligands are replaced by less hindered/basic chiral amido or alkyls. Concerning the interception of the generated lithium-zinc aryl species by aldehydes, the presence of amido ligands leads to side reactions/lower yields, and no clear improvement was observed if lithium-magnesium-zinc aryl species are used. Racemic mixtures to very low enantioselectivities were noted when chiral amido ligands were incorporated in the composition of the bases. Still with enantioselective aryl transfer to aldehyde as purpose, the deprotonating ability of mixed lithium-cobalt combinations containing amido and alkyl ligands were compared using anisole as substrate and anisaldehyde to trap the formed arylmetal species. As before, the deprotonating ability is reduced when 2,2,6,6-tetramethylpiperidino ligands are replaced by less hindered/basic alkyls or chiral amido. The trapping step using aldehydes being in this case more efficient, even in the presence of amido ligands, the alcohols were obtained in higher yields. With recourse to a lower interception temperature, and using only bis[(R)-1-phenylethyl]amino as ligands, 32 and 22% yield, and 69 and 65% ee were obtained using, respectively, anisaldehyde and 3,4,5-trimethoxybenzaldehyde to intercept the metalated anisole.
- Tilly, David,Snégaroff, Katia,Dayaker, Gandrath,Chevallier, Floris,Gros, Philippe C.,Mongin, Florence
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supporting information
p. 8761 - 8766
(2012/11/07)
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- FAMILY OF ARYL, HETEROARYL, O-ARYL AND O-HETEROARYL CARBASUGARS
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The present invention relates to a compound of the following formula (I): as well as its process of preparation, pharmaceutical and cosmetics composition comprising it and use thereof, notably as an inhibitor of the sodium-dependent glucose co-transporter, such as SGLTl, SGLT2 and SGLT3, in particular in the treatment or prevention of diabetes, and more particularly type-II diabetes, diabetes-related complications, such as arthritis of the lower extremities, cardiac infarction, renal insufficiency, neuropathy or blindness, hyperglycemia, hyperinsulinemia, obesity, hypertriglyceridemia, X syndrome and arteriosclerosis, as well as for its use as an anticancer, anti-infective, anti-viral, anti-thrombotic or anti- inflammatory drug, or for lightening, bleaching, depigmenting the skin, removing blemishes from the skin, particularly age spots and freckles, or preventing pigmentation of the skin.
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Page/Page column 58-59
(2012/12/13)
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- Deprotonative metalation of substituted aromatics using mixed lithium-cobalt combinations
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The deprotonation of anisole was attempted using different homo- and heteroleptic TMP/Bu mixed lithium-cobalt combinations. Using iodine to intercept the metalated anisole, an optimization of the reaction conditions showed that in THF at room temperature 2 equiv of base were required to suppress the formation of the corresponding 2,2′-dimer. The origin of the dimer was not identified, but its formation was favored with allyl bromide as electrophile. The metalated anisole was efficiently trapped using iodine, anisaldehyde, and chlorodiphenylphosphine, and moderately employing benzophenone, and benzoyl chloride. 1,2-, 1,3-, and 1,4-dimethoxybenzene were similarly converted regioselectively to the corresponding iodides. It was observed that 2-methoxy- and 2,6-dimethoxypyridine were more prone to dimerization than the corresponding benzenes when treated similarly. Involving ethyl benzoate in the metalation-iodination sequence showed that the method was not suitable to functionalize substrates bearing reactive functions.
- Dayaker, Gandrath,Chevallier, Floris,Gros, Philippe C.,Mongin, Florence
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experimental part
p. 8904 - 8910
(2011/01/04)
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- Deprotonative metalation of substituted benzenes and heteroaromatics using amino/alkyl mixed lithium-zinc combinations
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Different homoleptic and heteroleptic lithium-zinc combinations were prepared, and structural elements obtained on the basis of NMR spectroscopic experiments and DFT calculations. In light of their ability to metalate anisole, pathways were proposed to justify the synergy observed for some mixtures. The best basic mixtures were obtained either by combining ZnCl 2·TMEDA (TMEDA = N,N,N',N'tetramethylethylenediamine) with [Li(tmp)] (tmp = 2,2,6,6-tetramethylpiperidino; 3 equiv) or by replacing one of the tmp in the precedent mixture with an alkyl group. The reactivity of the aromatic lithium zincates supposedly formed was next studied, and proved to be substrate-, base-, and electrophile-dependent. The aromatic lithium zincates were finally involved in palladium-catalyzed cross-coupling reactions with aromatic chlorides and bromides.
- Snegaroff, Katia,Komagawa, Shinsuke,Chevallier, Floris,Gros, Philippe C.,Golhen, Stephane,Roisnel, Thierry,Uchiyama, Masanobu,Mongin, Florence
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experimental part
p. 8191 - 8201
(2010/09/11)
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- A new route to acyclic diaminocarbenes via lithium-halogen exchange
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A lithium - halogen exchange route has been developed to generate acyclic diaminocarbenes (ADC) from chloroamidinium salts. Convenient access to various ADC complexes (B, Rh, lr, Pd) stems from a one-pot transmetalation protocol. Formation of a carbenoid species is suggested by 1D and 2D NMR studies with a 13C-labeled chloroamidinium precursor and also by X-ray structures of transition metal-carbene complexes. Rh-ADC complex 4 is an effective catalyst for the 1,2-addition of aryl boronic acids to aryl aldehydes.
- Snead, David R.,Ghiviriga, Ion,Abboud, Khalil A.,Hong, Sukwon
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supporting information; experimental part
p. 3274 - 3277
(2009/12/01)
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- Orthoplatinated triarylphosphite as a highly efficient catalyst for addition reactions of arylboronic acids with aldehydes: Low catalyst loading catalysis and a new tandem reaction sequence
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(Chemical Equation Presented) Readily available, air/moisture-stable orthoplatinated triarylphosphite catalyzes the addition reactions of arylboronic acids with aldehydes with the catalyst loading as low as 0.01%. It also cataylzes a new tandem reaction of arylboronic acids with α,β- unsaturated aldehydes to form 1,3-diaryl-1-propanols. Our study provides a new paradigm for the application of orthoplatinated triarylphosphites, and may pave the road to develop other Pt(II) catalysts for such addition reactions and other tandem reactions with such addition reactions as part of the reaction sequence.
- Liao, Yuan-Xi,Xing, Chun-Hui,He, Ping,Hu, Qiao-Sheng
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supporting information; experimental part
p. 2509 - 2512
(2009/05/26)
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- Novel aromatic fluoroglycoside derivatives, medicaments containing these compounds, and the use thereof
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Novel aromatic fluoroglycoside derivatives, medicaments containing these compounds, and the use thereof. The invention relates to substituted aromatic fluoroglycoside derivatives of the formula I in which the radicals have the stated meanings, and their p
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Page/Page column 23
(2008/06/13)
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- Selective Thyromimetics. Cardiac-Sparing Thyroid Hormone Analogues Containing 3'-Arylmethyl Substituents
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Introduction of specific arylmethyl groups at the 3'-position of the thyroid hormone 3,3',5-triiodo-L-thyronine (T3), and its known hormonally active derivatives, gives liver-selective, cardiac-sparing thyromimetics, with potential utility as plasma cholesterol lowering agents.Selectivity-conferring 3'-substituents include substituted benzyl, e.g. p-hydroxybenzyl, and heterocyclic methyl, e.g. 2-oxo-1,2-dihydropyrid-5-ylmethyl and 6-oxo-1,6-dihydropyridazin-3-ylmethyl.Correlations between in vivo and in vitro receptor binding affinities show that liver/heart selectivity does not depend on receptor recognition but on penetration or access to receptors in vivo.QSAR studies of the binding data of a series of 20 3'-arylmethyl T3 analogues show that electronegative groups at the para position increase both receptor binding and selectivity in vivo.However, increasing 3'-arylmethyl hydrophobicity increases receptor binding but reduces selectivity.Substitution at ortho and meta positions reduces both binding and selectivity.Replacement of the 3,5-iodo groups by halogen or methyl maintains selectivity, with 3,5-dibromo analogues in particular having increased potency combined with oral bioavailability.Diphenyl thioether derivatives also have improved potency but are less orally active.At the 1-position, the D enantiomer retains selectivity, but removal of the α-amino group to give a propionic acid results in loss of selective thyromimetic activity.
- Leeson, Paul D.,Emmett, John C.,Shah, Virendra P.,Showell, Graham A.,Novelli, Ricardo,et al.
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p. 320 - 336
(2007/10/02)
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