- Alternating Radical Stabilities: A Convergent Route to Terminal and Internal Boronates
-
Pinacolato boronates (Bpin) with an empty p-orbital on boron stabilize an adjacent carbon radical, in contrast to diethanolamino boronates [B(DEA)] where the boron is sp3-hybridized. By alternately placing a pinacol or diethanolamine moiety on the boron atom, thus stabilizing or not stabilizing the corresponding adjacent radical, it is possible to control the behavior of α-boronyl xanthates and construct a large variety of terminal or internal boronates in a modular fashion. The remarkable tolerance of polar groups and the ability to introduce quaternary centers are particularly noteworthy features of this process.
- Huang, Qi,Michalland, Jean,Zard, Samir Z.
-
supporting information
p. 16936 - 16942
(2019/08/01)
-
- Synthesis of α-Borylated Ketones by Regioselective Wacker Oxidation of Alkenylboronates
-
As part of a program aimed at metal-catalyzed oxidative transformations of molecules with carbon-metalloid bonds, the synthesis of α-borylated ketones is reported via regioselective TBHP-mediated Wacker-type oxidation of N-methyliminodiacetic acid (MIDA)-protected alkenylboronates. The observed regioselectivity correlates with the hemilabile nature of the B-N dative bond in the MIDA boronate functional group, which allows boron to guide selectivity through a neighboring group effect.
- Corless, Victoria B.,Holownia, Aleksandra,Foy, Hayden,Mendoza-Sanchez, Rodrigo,Adachi, Shinya,Dudding, Travis,Yudin, Andrei K.
-
supporting information
p. 5300 - 5303
(2018/09/12)
-
- NOVEL INHIBITOR COMPOUNDS OF PHOSPHODIESTERASE TYPE 10A
-
The present invention relates to novel carboxamide compounds, pharmaceutical compositions containing them, and their use in therapy. The compounds possess valuable therapeutic properties and are particularly suitable for treating or controlling medical disorders selected from neurological disorders and psychiatric disorders, for ameliorating the symptoms associated with such disorders and for reducing the risk of such disorders
- -
-
-
- Organotrifluoroborate hydrolysis: Boronic acid release mechanism and an acid-base paradox in cross-coupling
-
The hydrolysis of potassium organotrifluoroborate (RBF3K) reagents to the corresponding boronic acids (RB(OH)2) has been studied in the context of their application in Suzuki-Miyaura coupling. The "slow release" strategy in such SM couplings is only viable if there is an appropriate gearing of the hydrolysis rate of the RBF3K reagent with the rate of catalytic turnover. In such cases, the boronic acid RB(OH)2 does not substantially accumulate, thereby minimizing side reactions such as oxidative homocoupling and protodeboronation. The study reveals that the hydrolysis rates (THF, H2O, Cs2CO 3, 55 °C) depend on a number of variables, resulting in complex solvolytic profiles with some RBF3K reagents. For example, those based on p-F-phenyl, naphthyl, furyl, and benzyl moieties are found to require acid catalysis for efficient hydrolysis. This acid-base paradox assures their slow hydrolysis under basic Suzuki-Miyaura coupling conditions. However, partial phase-splitting of the THF/H2O induced by the Cs2CO 3, resulting in a lower pH in the bulk medium, causes the reaction vessel shape, material, size, and stirring rate to have a profound impact on the hydrolysis profile. In contrast, reagents bearing, for example, isopropyl, β-styryl, and anisyl moieties undergo efficient "direct" hydrolysis, resulting in fast release of the boronic acid while reagents bearing, for example, alkynyl or nitrophenyl moieties, hydrolyze extremely slowly. Analysis of B-F bond lengths (DFT) in the intermediate difluoroborane, or the Swain-Lupton resonance parameter (R) of the R group in RBF3K, allows an a priori evaluation of whether an RBF3K reagent will likely engender "fast", "slow", or "very slow" hydrolysis. An exception to this correlation was found with vinyl-BF 3K, this reagent being sufficiently hydrophilic to partition substantially into the predominantly aqueous minor biphase, where it is rapidly hydrolyzed.
- Lennox, Alastair J. J.,Lloyd-Jones, Guy C.
-
supporting information; experimental part
p. 7431 - 7441
(2012/06/16)
-
- AUTOMATED SYNTHESIS OF SMALL MOLECULES USING CHIRAL, NON-RACEMIC BORONATES
-
Provided are methods for making and using chiral, non-racemic protected organoboronic acids, including pinene-derived iminodiacetic acid (PIDA) boronates, to direct and enable stereoselective synthesis of organic molecules. Also provided are methods for purifying PIDA boronates from solution. Also provided are methods for deprotection of boronic acids from their PIDA ligands. The purification and deprotection methods may be used in conjunction with methods for coupling or otherwise reacting boronic acids. Iterative cycles of deprotection, coupling, and purification can be performed to synthesize chiral, non-racemic compounds. The methods are suitable for use in an automated chemical synthesis process. Also provided is an automated small molecule synthesizer apparatus for performing automated stereoselective synthesis of chiral, non-racemic small molecules using iterative cycles of deprotection, coupling, and purification.
- -
-
Page/Page column 146
(2012/11/13)
-
- Pinene-derived iminodiacetic acid (PIDA): A powerful ligand for stereoselective synthesis and iterative cross-coupling of C(sp3) boronate building blocks
-
Efficient access to chiral C(sp3) boronates in stereochemically pure form is critical for realizing the substantial potential of such building blocks in complex-molecule synthesis. We herein report that a pinene-derived iminodiacetic acid (PIDA) ligand enables the highly diastereoselective synthesis of a wide range of oxiranyl C(sp3) boronates from the corresponding olefins. These oxiranyl PIDA boronates, in turn, can be readily transformed into unprecedented stable α-boryl aldehydes via a novel 1,2-migration of the boronate group that proceeds with complete maintenance of stereochemical purity. B-Protected haloboronic acids containing dual sp3-hybridized C centers are readily accessible via this platform, and the herein demonstrated capacity for stereocontrolled iterative C(sp3) cross-coupling with this novel type of bifunctional reagent to access a medicinally important chiral small-molecule target in highly enantioenriched form represents a substantial advance for the building-block-based approach to synthesis.
- Li, Junqi,Burke, Martin D.
-
supporting information; experimental part
p. 13774 - 13777
(2011/10/09)
-
- SLOW RELEASE OF ORGANOBORONIC ACIDS IN CROSS-COUPLING REACTIONS
-
A method of performing a chemical reaction includes reacting a compound selected from the group consisting of an organohalide and an organo-pseudohalide, and a protected organoboronic acid represented by formula (I) in a reaction mixture: R1-B-T; where R1 represents an organic group, T represents a conformationalIy rigid protecting group, and B represents boron having sp3 hybridization. When unprotected, the corresponding organoboronic acid is unstable by the boronic acid neat stability test. The reaction mixture further includes a base having a pKB of at least 1 and a pal ladium catalyst. The method further includes forming a cross-coupled product in the reaction mixture.
- -
-
Page/Page column 41, 43-44
(2010/04/27)
-
- A new approach to the synthesis of 4-hydroxyethylsulfonylstyrene
-
A new, more environmentally benign route to hydroxyethylsulfonylstyrene has been developed, starting from 4-bromobenzenethiol, involving a solventless thioether formation, water-based perborate oxidation, and Suzuki-Miyaura cross coupling with a vinylborate reagent.
- Grosjean, Christophe,Henderson, Andrew P.,Herault, Damien,Ilyashenko, Gennadiy,Knowles, Jonathan P.,Whiting, Andrew,Wright, Allen R.
-
body text
p. 434 - 441
(2010/04/22)
-
- Synthesis and biological evaluation of 6,7-disubstituted 4-aminopyrido[2,3-d]pyrimidines as adenosine kinase inhibitors
-
The synthesis and structure-activity relationship of a series of 6,7-disubstituted 4-aminopyrido[2,3-d]pyrimidines as novel non-nucleoside adenosine kinase inhibitors is described. A variety of substituents, primarily aryl, at the C6 and C7 positions of the pyridopyrimidine core were found to yield analogues that are potent inhibitors of adenosine kinase. In contrast to the 5,7-disubstituted and 5,6,7-trisubstituted pyridopyrimidine series, these analogues exhibited only modest potency to inhibit AK in intact cells.
- Perner, Richard J.,Lee, Chih-Hung,Jiang, Meiqun,Gu, Yu-Gui,DiDomenico, Stanley,Bayburt, Erol K.,Alexander, Karen M.,Kohlhaas, Kathy L.,Jarvis, Michael F.,Kowaluk, Elizabeth L.,Bhagwat, Shripad S.
-
p. 2803 - 2807
(2007/10/03)
-
- N-(4-substituted phenyl)-anthranilic acid hydroxamate esters
-
The present invention relates to oxygenated esters of 4-substituted-phenylamino benzhydroxamic acid derivatives, pharmaceutical compositions and methods of use thereof.
- -
-
-
- Synthesis of functionalized vinyl boronates via ruthenium-catalyzed olefin cross-metathesis and subsequent conversion to vinyl halides
-
Functionalized vinyl pinacol boronates suitable for Suzuki cross-coupling reactions are synthesized using ruthenium-catalyzed olefin cross-metathesis of 1-propenyl pinacol boronate and various alkenes, including functionalized and 1,1-disubstituted alkenes. The resultant boronate cross products are stereoselectively transformed into predominantly Z-vinyl bromides and E-vinyl iodides. The vinyl bromides may be synthesized in a two-step, one-pot synthesis from a variety of olefins, resulting in a Z-selective formal vinyl bromide cross-metathesis reaction.
- Morrill, Christie,Grubbs, Robert H.
-
p. 6031 - 6034
(2007/10/03)
-
- Process for preparing organic boronic acid derivatives using diboronic acid
-
The invention relates to a process for the preparation of organic boronic acid derivatives involving the reaction of an organic compound with diboronic acid in the presence of a Group 8-11 metal catalyst.
- -
-
-