Conversion of aldehydes to chiral amino boronates in an asymmetric style. Notably, the reaction is insensitive to substrate electronic effects with each electronrich and electronpoor substrates performing similarly. Though each meta and para substituted aryl aldehydes have been converted to aminoboronates with higher stereoselection, an orthosubstituted aryl aldehyde reacted within a nearracemic style. Fusedring substrates also reacted with good selectivity (compounds 1316). Importantly, even though the solutions are often hydrolyticallysensitive, the reaction mixtures could often be purified with waterdeactivated silica gel chromatography (see Supporting Info for these details).13 As alluded to above, one particular feature of this strategy for construction of amino boronates is the fact that the amino group could be acylated with a wide variety of various acyl donors.RuPhos Pd G2 Purity To explore the possibility of coupling with activated amino acid derivatives that could possibly be utilized in peptide synthesis, a tandem diboration/acylation sequence employing amino acid derivatives was examined. It was deemed that configurationally stable amino acid fluorides may possibly replace pivaolyl chloride applied in Table two. As depicted in equations four and five, this tactic proved extremely helpful and delivered peptidic amino boronates 17 and 18 in fantastic yield and without important epimerization of stereogenic centers.56842-95-6 web An extra essential feature in contemplating the utility from the amino borylation reaction would be the proclivity with the pinacol boronate to undergo conversion to the derived boronic acid. As depicted in equation six, this transformation is readily accomplished by remedy with BCl3.NIHPA Author Manuscript NIHPA Author Manuscript NIHPA Author Manuscript(4)J Am Chem Soc. Author manuscript; available in PMC 2014 June 26.Hong and MorkenPageNIHPA Author Manuscript NIHPA Author Manuscript NIHPA Author ManuscriptIn addition to serving as a easy route to aryl aminoboronic ester derivatives, the aminoborylation method described herein can give accelerated routes to chiral enantiomerically enriched benzhydryl amines. A recent report by Ohmura and Suginome described the stereoinvertive crosscoupling of Npivaloyl protected aminoboronates.14 As depicted in Scheme 2, this method was conveniently combined with aminoborylation to provide nonracemic 22, a potential precursor for the additional active enantiomer in the antihistamine agent cetirizine (Zyrtec). In summary, we report a catalytic enantioselective system for the amino borylation of aldehydes. This transformation can serve as a beginning point for the construction of amino boronic acidderived peptides. Additional studies addressing the scope and utility of this method are in progress.PMID:30125989 (five)(6)Supplementary MaterialRefer to Internet version on PubMed Central for supplementary material.AcknowledgmentsThe NIH (GM59417) is acknowledged for financial assistance; AllyChem is acknowledged for donations of B2(pin)2.
THE JOURNAL OF BIOLOGICAL CHEMISTRY VOL. 288, NO. 35, pp. 253625374, August 30, 2013 2013 by The American Society for Biochemistry and Molecular Biology, Inc. Published within the U.S.A.Histone Deacetylase 7 Promotes Tolllike Receptor 4dependent Proinflammatory Gene Expression in MacrophagesSReceived for publication, June 24, 2013 Published, JBC Papers in Press, July 12, 2013, DOI 10.1074/jbc.M113.Melanie R. Shakespear, Daniel M. Hohenhaus, Greg M. Kelly, Nabilah A. Kamal, Praveer Gupta, Larisa I. Labzin, Kate Schroder, Valerie Garceau Sheila Barbero, Abishek Iyer, David A. Hume.
