cas 1171891-31-8, 4-Methyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine

Articles about 1171891-31-8Total 5 be found

Article title
Article abstract
Author
Journal number and time
Download

Meta-Selective C-H Borylation of Benzamides and Pyridines by an Iridium-Lewis Acid Bifunctional Catalyst
We report herein the iridium-catalyzed meta-selective C-H borylation of benzamides by using a newly designed 2,2′-bipyridine (bpy) ligand bearing an alkylaluminum biphenoxide moiety. We also demonstrate the iridium-catalyzed C3-selective C-H borylation of pyridine with a 1,10-phenanthroline (Phen) ligand bearing an alkylborane moiety. It is proposed that the Lewis acid-base interaction between the Lewis acid moiety and the aminocarbonyl group or the sp2-hybridized nitrogen atom accelerates the reaction and controls the site-selectivity.
Yang, Lichen,Uemura, Nao,Nakao, Yoshiaki
supporting information
p. 7972 - 7979
(2019/05/22)

Iridium-catalyzed C-H borylation of heteroarenes: Scope, regioselectivity, application to late-stage functionalization, and mechanism
A study on the iridium-catalyzed C-H borylation of heteroarenes is reported. Several heteroarenes containing multiple heteroatoms were found to be amenable to C-H borylation catalyzed by the combination of an iridium(I) precursor and tetramethylphenanthroline. The investigations of the scope of the reaction led to the development of powerful rules for predicting the regioselectivity of borylation, foremost of which is that borylation occurs distal to nitrogen atoms. One-pot functionalizations are reported of the heteroaryl boronate esters formed in situ, demonstrating the usefulness of the reported methodology for the synthesis of complex heteroaryl structures. Application of this methodology to the synthesis and late-stage functionalization of biologically active compounds is also demonstrated. Mechanistic studies show that basic heteroarenes can bind to the catalyst and alter the resting state from the olefin-bound complex observed during arene borylation to a species containing a bound heteroarene, leading to catalyst deactivation. Studies on the origins of the observed regioselectivity show that borylation occurs distal to N-H bonds due to rapid N-H borylation, creating an unfavorable steric environment for borylation adjacent to these bonds. Computational studies and mechanistic studies show that the lack of observable borylation of C-H bonds adjacent to basic nitrogen is not the result of coordination to a bulky Lewis acid prior to C-H activation, but the combination of a higher-energy pathway for the borylation of these bonds relative to other C-H bonds and the instability of the products formed from borylation adjacent to basic nitrogen.
Larsen, Matthew A.,Hartwig, John F.
supporting information
p. 4287 - 4299
(2014/04/03)

Synthesis of biaryls through a one-pot tandem borylation/Suzuki-Miyaura cross-coupling reaction catalyzed by a palladacycle
The tricyclohexylphosphane adduct of cyclopalladated ferrocenylimine I exhibited high catalytic activity in the one-pot borylation/Suzuki-Miyaura coupling (BSC) reaction with low catalyst loading (2 mol-%). Various biaryls were obtained in good to excellent yields for 37 examples. This process was applied to aryl and heteroaryl halides (Br and Cl) containing a variety of functional groups and did not require an excess amount of phosphane ligand and the addition of the palladium catalyst in the second step. Cyclopalladated ferrocenylimine I exhibited high catalytic activity in the borylation/Suzuki- Miyaura coupling (BSC) reaction with low catalyst loading. Various unsymmetrical biaryls were obtained ingood to excellent yields in one pot. This protocol was applied to aryl and heteroaryl halides (Br and Cl) containing a variety of functional groups without adding catalyst in the second step. Copyright
Wang, Lianhui,Cui, Xiuling,Li, Jingya,Wu, Yusheng,Zhu, Zhiwu,Wu, Yangjie
experimental part
p. 595 - 603
(2012/03/09)

5-Thioxylopyranose Compounds
Compounds of 5-thioxylopyranose, preferably derivatives of the 5-thioxilopyranose type, a method for preparing such compounds, and the use of such compounds as an active ingredient in pharmaceutical compositions which are useful, in particular, for treati
-
Page/Page column 11

(2009/07/25)

Pyrrolopyrimidines and Pyrrolopyridines
Compounds of formula I in free or salt or solvate form, wherein X, T1, T3 and T4 have the meanings as indicated in the specification, are useful for treating diseases mediated by the ALK-5 and/or ALK-4 receptor. Pharmaceutical compositions that contain the compounds and processes for preparing the compounds are also described.
-
Page/Page column 50-52

(2009/07/25)