33733-83-4Relevant academic research and scientific papers
Cu-Catalyzed Phenol O-Methylation with Methylboronic Acid
Bartlett, Mairead E.,Chavez, Angela K.,Gaffney, Uma Bhagwat,Gorin, David J.,Lee, Joyce,Sharew, Betemariam,Wu, Miranda,Zhu, Yingchuan
supporting information, p. 5661 - 5664 (2021/11/11)
A Cu-catalyzed oxidative cross-coupling of phenols with methylboronic acid to form aryl methyl ethers has been developed, expanding the scope of Chan-Evans-Lam alkylation. Electron-deficient phenol derivatives with a broad array of functional groups are methylated in high yields. Increased reaction temperature and catalyst loading enables the methylation of substrates incorporating pyridine and dihydroquinolone motifs. Electron-rich phenol derivatives are poor substrates for the methylation; the characterization of C?H homodimerization products formed from these substrates illuminates a competing mechanistic pathway.
Synthesis of aryl ethers from benzoates through carboxylate-directed C-H-activating alkoxylation with concomitant protodecarboxylation
Bhadra, Sukalyan,Dzik, Wojciech I.,Goo?en, Lukas J.
supporting information, p. 2959 - 2962 (2013/04/10)
One in, one out: In the presence of a copper/silver bimetallic catalyst system, aromatic carboxylate salts undergo ortho C-H alkoxylation with concomitant loss of the carboxylate directing group in a protodecarboxylation step (see scheme, FG=functional group). This process provides a convenient synthetic access to the important class of aromatic ethers from widely available carboxylic acids. Copyright
Synthesis of aryl ethers from aromatic carboxylic acids
Bhadra, Sukalyan,Dzik, Wojciech I.,Goossen, Lukas J.
supporting information, p. 2387 - 2390 (2013/09/23)
A silver/copper bimetallic catalyst system promotes the decarboxylative Chan-Evans-Lam alkoxylation of ortho-substituted aromatic carboxylate salts with tetraalkyl orthosilicates or triaryl borates. Non-ortho-substituted carboxylates are alkoxylated via an ortho-C-H-alkoxylation with concomitant cleavage of the carboxylate directing group via protodecarboxylation. This way, meta-substituted carboxylates are converted into para-substituted alkoxyarenes and vice versa. The combined processes provide a convenient synthetic entry to the important class of aromatic ethers from widely available carboxylic acids.
Access to "friedel-Crafts-Restricted" tert -alkyl aromatics by activation/methylation of tertiary benzylic alcohols
Hartsel, Joshua A.,Craft, Derek T.,Chen, Qiao-Hong,Ma, Ming,Carlier, Paul R.
, p. 3127 - 3133 (2012/05/20)
Herein we describe a two-step protocol to prepare m-tert-alkylbenzenes. The appropriate tertiary benzylic alcohols are activated with SOCl2 or concentrated HCl and then treated with trimethylaluminum, affording the desired products in 68-97% yields (22 examples). This reaction sequence is successful in the presence of a variety of functional groups, including acid-sensitive and Lewis-basic groups. In addition to t-Bu groups, 1,1-dimethylpropyl and 1-ethyl-1-methylpropyl groups can also be installed using this method.
Nickel-catalyzed Kumada cross-coupling reactions of tertiary alkylmagnesium halides and aryl bromides/triflates
Joshi-Pangu, Amruta,Wang, Chao-Yuan,Biscoe, Mark R.
supporting information; experimental part, p. 8478 - 8481 (2011/06/25)
We report a Ni-catalyzed process for the cross-coupling of tertiary alkyl nucleophiles and aryl bromides. This process is extremely general for a wide range of electrophiles and generally occurs with a ratio of retention to isomerization >30:1. The same procedure also accommodates the use of aryl triflates, vinyl chlorides, and vinyl bromides as the electrophilic component.
Nickel-catalyzed cross-coupling of aryl bromides with tertiary grignard reagents utilizing donor-functionalized N-heterocyclic carbenes (NHCs)
Lohre, Claudia,Droege, Thomas,Wang, Congyang,Glorius, Frank
supporting information; experimental part, p. 6052 - 6055 (2011/06/25)
Metal-catalyzed cross-coupling reactions are among the most important transformations in organic synthesis, allowing the efficient construction of complex structures from simpler, readily available building blocks.Many applications in large and small-scale synthesis can be found in different areas such as agrochemicals, pharmaceuticals and supramolecular chemistry. Whereas the coupling of sp2-hybridized carbon atoms in either reaction partner is well established, the use of CACHTUNGTRENUNG(sp3)-hybridized substrates presents some challenges. Catalytic cross-coupling of sterically hindered tertiary alkyl substrates is especially difficult, generally resulting in low yields, and thus, only few reports exist.[27] A big challenge in this field is not only to get the required level of reactivity, but also to overcome competing pathways like β-hydride elimination, hydrodehalogenation or isomerization
MODULATORS OF CCR9 RECEPTOR AND METHODS OF USE THEREOF
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Page/Page column 24-25, (2010/03/02)
Provided are compounds that are modulators of CCR9 receptor activity, compositions containing the compounds and methods of use of the compounds and compositions. In certain embodiments, provided are methods for treating or ameliorating diseases associated
Synthesis of novel structurally simplified estrogen analogues with electron-donating groups in ring A
Tietze, Lutz F.,Vock, Carsten A.,Krimmelbein, Ilga K.,Nacke, Linda
experimental part, p. 2040 - 2060 (2009/12/27)
A library of 25 novel estrogen analogues were prepared in five to eight steps from mostly commercially available substituted anisoles via bromination, formylation, Corey-Fuchs reaction, elimination, and Sonogashira reaction. Georg Thieme Verlag Stuttgart.
Radical aromatic substitution with benzene chromiumtricarbonyl
Byers, Jeffrey H.,Neale, Nathan R.,Bradford Alexander,Gangemi, Stephen P.
, p. 7903 - 7905 (2008/03/27)
Radical aromatic substitution of tert-butyl groups for hydrogen on simple arene chromiumtricarbonyl complexes was accomplished. Preexisting tert-butyl groups and methoxy groups directed incoming radicals primarily to the meta-position, and methoxy groups diminished the rate of substitution by roughly tenfold.
Self-Initiated Autoxidation of a Sterically Crowded Cycloheptatriene Derivative via Norcaradienyloxyl Radicals
Kitagawa, Toshikazu,Miyabo, Atsushi,Fujii, Hideki,Okazaki, Takao,Mori, Tetsuya,Matsudou, Masaki,Sugie, Takeshi,Takeuchi, Ken'ichi
, p. 888 - 892 (2007/10/03)
An extremely crowded cycloheptatriene derivative, 1,3,5-tri-tert-butyl-7-(9-phenyl-9-fluorenyl)-l,3,5-cycloheptatriene (1), underwent autoxidation at 25 °C in cyclohexane to give 4-tert-butyl-2-pivaloylphenol (3) (33%), 5-tert-butyl-2-pivaloylphenol (4) (11%), 1,3,5-tri-tert-butylbenzene (5) (5%), tert-butyl 9-phenyl-9-fluorenyl peroxide (6) (44%), bis(9-phenyl-9-fluorenyl) peroxide (7) (7%), 1,1′,3,3′,5,5′-hexa-tert-butyl-7,′-bicycloheptatriene (8) (2%), and carbon monoxide (4%). ESR studies showed that 1 dissociates into l,3,5-tri-tert-butyltropyl radical (11) and 9-phenylfluorenyl radical (12) at 25-85 °C. The enthalpy and entropy of dissociation were determined to be 23.3 kcal/mol and 22.0 cal/mol·K, respectively. The formation of 3-5 can be explained by a mechanism involving attack of molecular oxygen to 11 and subsequent valence tautomerism of cycloheptatrienyloxyl radicals to norcaradienyloxyl radicals.
