867182-07-8Relevant academic research and scientific papers
Asymmetric Synthesis of α-Aminoboronates via Rhodium-Catalyzed Enantioselective C(sp3)-H Borylation
Reyes, Ronald L.,Sato, Miyu,Iwai, Tomohiro,Sawamura, Masaya
supporting information, p. 589 - 597 (2020/01/22)
α-Aminoboronic acids, isostructural boron analogues of α-amino acids, have received much attention because of the important biomedical applications implicated for compounds containing this structure. Additionally, the inherent versatility of α-aminoboronic acids as synthetic intermediates through diverse carbon-boron bond transformations makes the efficient synthesis of these compounds highly desirable. Here, we present a Rh-monophosphite chiral catalytic system that enables a highly efficient enantioselective borylation of N-adjacent C(sp3)-H bonds for a range of substrate classes including 2-(N-alkylamino)heteroaryls and N-alkanoyl- or aroyl-based secondary or tertiary amides, some of which are pharmaceutical agents or related compounds. Various stereospecific transformations of the enantioenriched α-aminoboronates, including Suzuki-Miyaura coupling with aryl halides and the Rh-catalyzed reaction with an isocyanate derivative of α-amino acid, affording a new peptide chain elongation method, have been demonstrated. As a highlight of this work, the borylation protocol was successfully applied to the catalyst-controlled site-selective and stereoselective C(sp3)-H borylation of an unprotected dipeptidic compound, allowing remarkably streamlined synthesis of the anti-cancer drug molecule bortezomib and offering a straightforward route for the synthesis of privileged molecular architectures.
α-Amidobenzylation of aryl and alkenyl halides via palladium-catalyzed Suzuki-Miyaura coupling with α-(acylamino) benzylboronic esters
Ohmura, Toshimichi,Awano, Tomotsugu,Suginome, Michinori
, p. 664 - 665 (2011/04/22)
The Suzuki-Miyaura coupling of α-(acetylamino)benzylboronic esters with aryl and alkenyl halides has been achieved using a Pd/P(t-Bu)3 catalyst with KF and H2O in 1,4-dioxane, giving α-substituted benzylamines in high yields. Copyright
Enantiomeric excess of 1,2-diols by formation of cyclic boronates: An improved method
Morandi, Stefania,Caselli, Emilia,Forni, Arrigo,Bucciarelli, Maria,Torre, Giovanni,Prati, Fabio
, p. 2918 - 2926 (2007/10/03)
A reliable method for determining the enantiomeric composition of 1,2-diols by the formation of diastereomeric cyclic esters with boronic acid is described. Starting from a previously reported structure of boronic chiral derivatizing agent (CDA), seven structurally related racemic CDAs were synthesized and their discriminating ability towards diols measured. The most promising amongst these was synthesized in its enantiomerically pure form according to Matteson's protocol for the stereoselective homologation of pinanediol boronates; this CDA quantitatively and rapidly reacts with 1,2-diols in very mild conditions affording a couple of diastereoisomers, whose composition can be determined via 1H NMR analysis. In particular, an attractive feature is that the resonance used for the analysis originated from the CDA as a couple of baseline-separated singlets (Δδ up to 0.3 ppm) is useful for integration.
