- Nickel(II)-Catalyzed Addition of Aryl and Heteroaryl Boroxines to the Sulfinylamine Reagent TrNSO: The Catalytic Synthesis of Sulfinamides, Sulfonimidamides, and Primary Sulfonamides
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We report a redox-neutral Ni(II)-catalyzed addition of (hetero)aryl boroxines to N-sulfinyltritylamine (TrNSO). The reactions use a catalyst generated from the combination of commercial, air-stable NiCl2·(glyme) and a commercially available bipyridine lig
- Lo, Pui Kin Tony,Willis, Michael C.
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supporting information
p. 15576 - 15581
(2021/10/02)
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- Copper-Catalyzed Asymmetric Arylation of N-Heteroaryl Aldimines: Elementary Step of a 1,4-Insertion
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Copper complexes of monodentate phosphoramidites efficiently promote asymmetric arylation of N-azaaryl aldimines with arylboroxines. DFT calculations and experiments support an elementary step of 1,4-insertion in the reaction pathway, a step in which an aryl-copper species adds directly across four atoms of C=N?C=N in the N-azaaryl aldimines.
- Wu, Chunlin,Qin, Xurong,Moeljadi, Adhitya Mangala Putra,Hirao, Hajime,Zhou, Jianrong Steve
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supporting information
p. 2705 - 2709
(2019/02/06)
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- Copper-mediated anomeric: O -arylation with organoboron reagents
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Copper-mediated couplings of arylboroxines with glycosyl hemiacetals furnish O-aryl glycosides via Csp2-O bond formation. The method enables the anomeric O-arylation of protected pyranose and furanose derivatives, and is tolerant of functionalized arylboroxine partners. Whereas mixtures of anomers are formed from glucopyranose, galactopyranose and arabinofuranose hemiacetals, the α-anomer is generated selectively from mannopyranose and mannofuranose-derived substrates.
- Dimakos, Victoria,Liu, Jacklyn J. W.,Ge, Zhenlu,Taylor, Mark S.
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supporting information
p. 5671 - 5674
(2019/06/18)
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- Unveiling the role of boroxines in metal-free carbon-carbon homologations using diazo compounds and boronic acids
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By means of computational and experimental mechanistic studies the fundamental role of boroxines in the reaction between diazo compounds and boronic acids was elucidated. Consequently, a selective metal-free carbon-carbon homologation of aryl and vinyl boroxines using TMSCHN2, giving access to TMS-pinacol boronic ester products, was developed.
- Bomio, Claudio,Kabeshov, Mikhail A.,Lit, Arthur R.,Lau, Shing-Hing,Ehlert, Janna,Battilocchio, Claudio,Ley, Steven V.
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p. 6071 - 6075
(2017/08/29)
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- Palladium(II)-Catalyzed Enantioselective Synthesis of α-(Trifluoromethyl)arylmethylamines
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We describe a method for the synthesis of α-(trifluoromethyl)arylmethylamines that consists of the palladium(II)-catalyzed addition of arylboroxines to imines derived from trifluoroacetaldehyde. Palladium acetate is used as a catalyst with electron-neutral or electron-rich arylboroxines, and it was found that addition of an ammonium or silver salt was crucial to promote the reaction of electron-poor boroxines. With (S)-t-Bu-PyOX as the chiral ligand, this method delivers a variety of α-trifluoromethylated amines in 57-91% yield and with greater than 92% ee in most cases.
- Johnson, Thomas,Luo, Bo,Lautens, Mark
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p. 4923 - 4930
(2016/07/06)
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- Rhodium-Catalyzed Asymmetric Arylation/Defluorination of 1-(Trifluoromethyl)alkenes Forming Enantioenriched 1,1-Difluoroalkenes
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The reaction of 1-(trifluoromethyl)alkenes (CF3CH=CHR) with arylboroxines (ArBO)3 in the presence of a chiral diene-rhodium catalyst gave high yields of chiral 1,1-difluoroalkenes (CF2=CHC?HArR) with high enantioselectivity (≥95% ee). The reaction is assumed to proceed through β-fluoride elimination of a β,β,β-trifluoroalkylrhodium intermediate that is generated by arylrhodation of the 1-(trifluoromethyl)alkene.
- Huang, Yinhua,Hayashi, Tamio
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supporting information
p. 12340 - 12343
(2016/10/07)
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- Oxidative coupling of aryl boron reagents with sp3-carbon nucleophiles: The enolate chan–evans–lam reaction
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Reported is a versatile new oxidative method for the arylation of activated methylene species. Under mild reaction conditions (RT to 40°C), Cu(OTf)2mediates the selective coupling of functionalized aryl boron species with a variety of stabilized sp3-nucleophiles. Tertiary malonates and amido esters can be employed as substrates to generate quaternary centers. Complementing either traditional cross-coupling or SNAr protocols, the transformation is chemoselective in the presence of halogen electrophiles, including aryl bromides and iodides. Substrates bearing amide, sulfonyl, and phosphonyl groups, which are not amenable to coupling under mild Hurtley-type conditions, are suitable reaction partners.
- Moon, Patrick J.,Halperin, Heather M.,Lundgren, Rylan J.
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supporting information
p. 1894 - 1898
(2016/12/03)
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- Oxidative Heck desymmetrisation of 2,2-disubstituted cyclopentene-1,3-diones
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Oxidative Heck couplings have been successfully developed for 2,2-disubstituted cyclopentene-1,3-diones. The direct coupling onto the 2,2-disubstituted cyclopentene-1,3-dione core provides a novel expedient way of enantioselectively desymmetrising all-carbon quaternary centres. This journal is
- Walker,Lamb,Beattie,Nikodemiak,Lee
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supporting information
p. 4089 - 4092
(2015/03/30)
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- Asymmetric Synthesis of Triarylmethanes by Rhodium-Catalyzed Enantioselective Arylation of Diarylmethylamines with Arylboroxines
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The reaction of racemic diarylmethylamines, (Ar1Ar2CHNR2), where Ar1 is substituted with a 2-hydroxy group, with arylboroxines (Ar3BO)3 in the presence of a chiral diene-rhodium catalyst gave high yields of chiral triarylmethanes (Ar1Ar2CH?Ar3) with high enantioselectivity (up to 97% ee). The reaction is assumed to proceed through o-quinone methide intermediates which undergo Rh-catalyzed asymmetric 1,4-addition of the arylboron reagents.
- Huang, Yinhua,Hayashi, Tamio
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supporting information
p. 7556 - 7559
(2015/07/01)
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- Copper-Catalyzed Cyanation of Aryl- and Alkenylboronic Reagents with Cyanogen Iodide
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Direct catalytic cyanation of organoboronic acids with cyanogen iodide has been achieved by using a copper-bipyridine catalyst system. The cyanation reaction is likely to occur through two catalytic cycles: copper(II)-catalyzed iodination of organoboronic acids and the following cyanidocopper(I)-mediated cyanation of organic iodides.
- Okamoto, Kazuhiro,Sakata, Naoki,Ohe, Kouichi
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supporting information
p. 4670 - 4673
(2015/10/12)
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- Direct Amidation of N-Boc- and N-Cbz-Protected Amines via Rhodium-Catalyzed Coupling of Arylboroxines and Carbamates
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N-Boc- and N-Cbz-protected amines are directly converted into amides by a novel rhodium-catalyzed coupling of arylboroxines and carbamates, replacing the traditional two-step deprotection-condensation sequence. Both protected anilines and aliphatic amines are efficiently transformed into a wide variety of secondary benzamides, including sterically hindered and electron-deficient amides, as well as in the presence of acid-labile and reducible functional groups.
- Lim, Diane S. W.,Lew, Tedrick T. S.,Zhang, Yugen
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supporting information
p. 6054 - 6057
(2016/01/09)
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- Rhodium-catalyzed asymmetric hydroarylation of 3-pyrrolines giving 3-arylpyrrolidines: Protonation as a key step
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A hydroxorhodium complex coordinated with (R)-segphos was found to catalyze the hydroarylation of 3-pyrrolines with arylboroxines under neutral conditions to give 3-arylpyrrolidines with high enantioselectivity in high yields.
- So, Chau Ming,Kume, Satoshi,Hayashi, Tamio
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supporting information
p. 10990 - 10993
(2013/08/23)
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- Scalable synthesis of oxazolones from propargylic alcohols through multistep palladium(II) catalysis: β-selective oxidative heck coupling of cyclic sulfonyl enamides and aryl boroxines
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A whale of a scale: The title oxidative Heck coupling proceeded with unusual β selectivity to generate a variety of branched substituted oxazolones (see scheme; Ts=p-toluenesulfonyl). The three-step synthesis from readily available starting materials with a simple palladium catalyst and inexpensive reagents could be carried out in a single reaction vessel or scaled up for the preparation of large amounts of these amino acid precursors. Copyright
- Alamsetti, Santosh Kumar,Persson, Andreas K. A.,Jiang, Tuo,Baeckvall, Jan-E.
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supporting information
p. 13745 - 13750
(2014/01/06)
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- Transition-metal-free electrophilic amination of arylboroxines
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A transition-metal-free strategy to construct C(sp2)-N bonds using arylboroxines and O-benzoyl hydroxylamines as coupling partners has been developed. This transformation provides a useful method to access various aromatic amines.
- Xiao, Qing,Tian, Leiming,Tan, Renchang,Xia, Ying,Qiu, Di,Zhang, Yan,Wang, Jianbo
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supporting information; experimental part
p. 4230 - 4233
(2012/09/22)
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- Rh-catalyzed addition of arylboroxines to cyclic N -(Isopropanesulfinyl) ketimines
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Arylboroxines, which are easily accessed by drying commercially available arylboronic acids, are added to N-(isopropanesulfinyl)ketimines derived from cyclohexanone, N-Boc-piperidin-4-one, and tetrahydropyran-4-one in high yields and with excellent functional group compatibility via rhodium catalysis. These results contrast with additions to the corresponding ketimines incorporating the larger N-tert-butanesulfinyl group, which give considerably lower yields. Efficient two-step preparation of racemic isopropanesulfinamide from inexpensive isopropyl disulfide and recycling of the isopropanesulfinyl group from the addition products are also described.
- Jung, Hyung Hoon,Buesking, Andrew W.,Ellman, Jonathan A.
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p. 9593 - 9600,8
(2012/12/12)
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- Rh-catalyzed addition of arylboroxines to cyclic N -(Isopropanesulfinyl) ketimines
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Arylboroxines, which are easily accessed by drying commercially available arylboronic acids, are added to N-(isopropanesulfinyl)ketimines derived from cyclohexanone, N-Boc-piperidin-4-one, and tetrahydropyran-4-one in high yields and with excellent functional group compatibility via rhodium catalysis. These results contrast with additions to the corresponding ketimines incorporating the larger N-tert-butanesulfinyl group, which give considerably lower yields. Efficient two-step preparation of racemic isopropanesulfinamide from inexpensive isopropyl disulfide and recycling of the isopropanesulfinyl group from the addition products are also described.
- Jung, Hyung Hoon,Buesking, Andrew W.,Ellman, Jonathan A.
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p. 9593 - 9600
(2013/01/15)
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- Bis-sulfamyl imines: Potent substrates for asymmetric additions of arylboroxines under rhodium catalysis
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Bis-sulfamyl imines are shown to be potentially ideal substrates for rhodium-catalysed asymmetric additions of arylboron nucleophiles as they show: (i) near perfect enantioselectivities (11 examples, 98-99+% ee), (ii) good to excellent diastereoselectivities (10-32:1 rac:meso), and (iii) high functional group tolerance in removal of the low molecular weight protecting group via mild heating in aqueous pyridine.
- Crampton, Rosemary,Woodward, Simon,Fox, Martin
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supporting information; experimental part
p. 903 - 906
(2011/06/19)
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- Highly functional group compatible Rh-catalyzed addition of arylboroxines to activated N-tert-butanesulfinyl ketimines
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The rhodium-catalyzed addition of readily accessible arylboroxines to N-tert-butanesulfinyl ketimines derived from oxetan-3-one, N-Boc-azetidin-3-one, and isatins proceeds in high yields with excellent functional group compatibility. Moreover, high diastereoselectivities are observed for the additions to the N-sulfinyl ketimines derived from isatins.
- Jung, Hyung Hoon,Buesking, Andrew W.,Ellman, Jonathan A.
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supporting information; experimental part
p. 3912 - 3915
(2011/09/16)
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- Asymmetric additive-free aryl addition to aldehydes using perhydrobenzoxazines as ligands and boroxins as aryl source
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A highly efficient enantioselective aryl addition to aldehydes using boroxins as aryl source and conformationally restricted perhydro-1,3- benzoxazines as ligands is reported. Both enantiomeric forms of chiral arylphenylmethanols and 1,1′-disubstituted diarylmethanols are afforded with excellent yields and enantioselectivities using the same ligand by means of an appropriate combination of boroxin and aromatic aldehyde. The enantiocontrol is not significantly influenced by electronic effects or steric hindrance, even with substituted boroxins. Very homogeneous ee's are reached when substituted arylboroxins are employed, without the use of any class of additive or pre-treatment.
- Infante, Rebeca,Nieto, Javier,Andres, Celia
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body text
p. 6691 - 6699
(2011/11/04)
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- Chiral tetrafluorobenzobarrelenes as effective ligands for rhodium-catalyzed asymmetric 1,4-addition of arylboroxines to β,β-disubstituted α,β-unsaturated ketones
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(Chemical Equotion Present) Lock, Stock and Two Smoking Barrelenes: The rhodium-catalyzed 1,4-addition of readily available arylboronic acid anhydrides to simple β,β-disubstituted α,βunsaturated ketones creates quaternary carbon stereocenters with high enantiomeric excesses using a chiral tetrafluorobenzobarrelene ligand.
- Shintani, Ryo,Takeda, Momotaro,Nishimura, Takahiro,Hayashi, Tamio
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supporting information; experimental part
p. 3969 - 3971
(2010/09/03)
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- Construction of polysubstituted olefins through Ni-Catalyzed direct activation of Alkenyl C-O of substituted alkenyl acetates
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(Figure Presented) Reliable companion: For the first time cross-coupling between alkenyl acetates and arylboroxines/PhZnCl has been developed via Ni catalysis. Alkenyl acetates could be well-differ-entiated from aryl acetates (see scheme). This reliable method provides a convenient pathway to construct polysubstituted styrene derivatives.
- Sun, Chang-Liang,Yang, Wang,Xiao, Zhou,Wu, Zhen-Hua,Li, Bi-Jie,Guan, Bing-Tao,Shi, Zhang-Jie
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supporting information; body text
p. 5844 - 5847
(2010/09/03)
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- Chiral 1,1′-binaphthylazepine-derived amino alcohol catalyzed asymmetric aryl transfer reactions with boroxine as aryl source
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Using chiral 1,1′-binaphthylazepine-derived amino alcohol as catalyst, the direct addition of in situ prepared arylzinc (with triphenylboroxine as aryl source) to various aryl aldehydes can afford optically active diarylmethanols in high yields and enantioselectivities (up to 96%).
- Liu, Can,Guo, Zong-Liang,Weng, Jiang,Lu, Gui,Chan, Albert S. C.
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experimental part
p. 159 - 164
(2010/09/04)
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- SYNTHESIS AND CRYSTALLINE FORMS OF CB-1 ANTAGONIST/INVERSE AGONIST
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The present invention relates to a process for producing crystalline 3-[(1S)-1-(1-{(S)-(4-chlorophenyl)[3-(5-oxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)phenyl]methyl} azetidin-3-yl)-2-fluoro-2-methylpropyl]-5-fluorobenzonitrile, and novel salts, solvates, hydrates and polymorphs thereof.
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Page/Page column 29; 30; 33
(2009/05/30)
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- Steric tuning of the amidomonophosphane-rhodium(l) catalyst in asymmetric addition of arylboroxines to n-phosphinoyl aldimines
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Highly enantioselective rhodium-catalyzed addition of arylboroxlnes to N-phosphinoylaldimines was realized by the steric tuning of a dlphenylphosphorus moiety to a di(o-tolyl)phosphorus moiety of a chiral amidomonophosphane. The presence of MS 4 A in a 5:1 solvent mixture of dioxane-propanol was essential to afford the corresponding dlarylmethylamines In high yield.
- Hao, Xinyu,Kuriyama, Masami,Chen, Qian,Yamamoto, Yasutomo,Yamada, Ken-Ichi,Tomioka, Kiyoshi
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body text
p. 4470 - 4473
(2009/12/24)
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- Synthetic and X-ray diffraction studies of borosiloxane cages [R′Si(ORBO)3SiR′] and the adducts of [ButSi{O(PhB)O}3SiBut] with pyridine or N,N,N′,N′-tetramethylethylenediamine
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Eleven borosiloxane [R′Si(ORBO)3SiR′] compounds where R′ = But and R = Ph (1), 4-PhC6H4 (2), 4-ButC6H4 (3), 3-NO2C6H4 (4), 4-CH(O)C6H4 (5), CpFeC5H4 (6), 4-C(O)CH3C6H4 (7), 4-ClC6H4 (8), 2,4-F2C6H3 (9), and R′ = cyclo-C6H11 and R = Ph (10), and 4-BrC6H4 (11) have been synthesized and characterized by spectroscopic (IR, NMR), mass spectrometric and, for compounds where R′ = But and R = 4-PhC6H4 (2), 4-ButC6H4 (3), 3-NO2C6H4 (4), CpFeC5H4 (6) and 2,4-F2C6H3 (9), X-ray diffraction studies. These compounds contain trigonal planar RBO2 and tetrahedral R′SiO3 units located around 11-atom "spherical" Si2O6B3 cores. The dimensions of the Si2O6B3 cores in compounds 2, 3, 4, 6 and 9 are remarkably similar. The reaction between [ButSi{O(PhB)O}3SiBut] (1), and excess pyridine yields the 1:1 adduct [ButSi{O(PhB)O}SiBut]. NC5H5 (12) while the reaction between 1 and N,N,N′,N′-tetramethylethylenediamine in equimolar amounts affords a 2:1 borosiloxane:amine adduct [ButSi{O(PhB)O}3SiBut]2 · Me2NCH2CH2NMe2 (13). Compounds 12 and 13 were characterised with IR and (1H, 13C and11B) NMR spectroscopies and the structure of the pyridine complex 12 was determined with X-ray techniques.
- Ferguson, George,Lawrence, Simon E.,Neville, Lorraine A.,O'Leary, Brian J.,Spalding, Trevor R.
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p. 2482 - 2492
(2008/10/09)
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- Catalyzed asymmetric aryl transfer reactions to aldehydes with boroxines as aryl source
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Asymmetric aryl transfer of triphenylboroxin to a set of aryl aldehydes has been carried out in the presence of chiral amino alcohols derived from (S)-proline with high enantioselectivity. Substituted phenyl boroxins were also used as aryl source in asymmetric arylation of benzaldehyde.
- Wu, Xiaoyu,Liu, Xinyuan,Zhao, Gang
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p. 2299 - 2305
(2007/10/03)
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- Formation of boroxine: Its stability and thermodynamic parameters in solution
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Condensation of three boronic acids proceeding at room temperature gave their corresponding boroxines; NMR spectral measurements revealed that the reaction was reversible at room temperature, that electron-donating groups supported the formation of boroxine, and that entropically driven forces promoted the formation of boroxine in solution.
- Tokunaga, Yuji,Ueno, Hiroki,Shimomura, Youji,Seo, Toshihiro
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p. 787 - 790
(2007/10/03)
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