135884-31-0Relevant academic research and scientific papers
Synthesis and structural characterization of a trispyrrole iron(II) complex K(dme)4[tpaMesFe] and application in nitrous oxide dependent coupling reactions
Weidauer, Maik,Irran, Elisabeth,Enthaler, Stephan
, p. 1 - 4 (2015)
A new synthetic route to the trispyrrole iron(II) complex {K(dme)4[tpaMesFe]} was established starting from BOC-protected pyrrol via synthesis of the corresponding boronic acid, cross-coupling reaction, deprotection, triple Mannich reaction, a deprotonation and finally a salt metathesis. The complex was characterized and applied in iron-catalyzed coupling reactions. In more detail, with catalytic amounts of K(dme)4[tpaMesFe] the homo-coupling of aromatic Grignard reagents as well as the hetero-coupling of aromatic Grignard reagents were feasible. Noteworthy, to force the reaction nitrous oxide was added to realize yields up to 93% at mild reaction conditions.
Synthesis and structure-activity relationship of novel 6-aryl-1,4- dihydrobenzo[d][1,3]oxazine-2-thiones as progesterone receptor modulators leading to the potent and selective nonsteroidal progesterone receptor agonist tanaproget
Fensome, Andrew,Bender, Reinhold,Chopra, Rajiv,Cohen, Jeff,Collins, Mark A.,Hudak, Valerie,Malakian, Karl,Lockhead, Susan,Olland, Andrea,Svenson, Kristine,Terefenko, Eugene A.,Unwalla, Ray J.,Wilhelm, James M.,Wolfrom, Scott,Zhu, Yuan,Zhang, Zhiming,Zhang, Puwen,Winneker, Richard C.,Wrobel, Jay
, p. 5092 - 5095 (2005)
Tanaproget represents a potential first-in-class nonsteroidal PR agonist for contraception with improved safety and side effect profiles versus currently available steroidal oral contraceptives. Additional SAR, biological activity, and structural information from a tanaproget/hPR-LBD (hPR-LBD = human progesterone receptor ligand binding domain) cocrystal structure will also be presented.
Direct selection for catalysis from combinatorial antibody libraires using a boronic acid probe: Primary amide bond hydrolysis
Gao, Changshou,Lavey, Brian J.,Lo, Chih-Hung L.,Datta, Anita,Wentworth Jr., Paul,Janda, Kim D.
, p. 2211 - 2217 (1998)
This report describes a joint hybridoma and combinatorial antibody library approach to elicit catalysts for primary amide bond hydrolysis. By immunization with a trigonal boronic acid hapten 3a and construction of a Fab (antigen-binding fragment) library, a diastereoselective catalyst for hydrolysis of the tripeptide primary amide substrate la was selected. In contrast, no antibody catalyst was isolated by standard hybridoma methods of monoclonal antibody production following immunizations with hapten 3a. The active Fab, BL25, obeys Michaelis-Menten kinetic behavior (k(cat)/k(uncat) ca. 4 x 104, K(m) = 150 μM) and is competitively inhibited by a boronic acid hapten analog 3b (K(i) = 9 μM). Kinetic and binding studies both point to Fab selection of a hydrated tetrahedral anionic form of the boronic acid hapten 3a which serves to mimic the putative transition state 4 for catalysis of water addition to the primary amide bond. Fab-BL25 exhibits exquisite substrate selectivity, as a methyl ester analog of 1a is not accepted as a substrate. This work emphasises the power of the direct selection strategy when linked to screening of antibody combinatorial libraries and discloses the utility of boronic acids as haptens in acyl transfer processes.
Hydrogen-bonded cyclic dimers at large compression: The case of 1h-pyrrolo[3,2-h]quinoline and 2-(2′-pyridyl)pyrrole
Chumak, Taisiia,Kurzyd?owski, Dominik,Listkowski, Arkadiusz,Rogo?a, Jakub
, (2021)
1H-pyrrolo[3,2-h]qinoline (PQ) and 2-(2′-pyridyl)pyrrole (PP) are important systems in the study of proton-transfer reactions. These molecules possess hydrogen bond donor (pyrrole) and acceptor (pyridine) groups, which leads to the formation of cyclic dimers in their crystals. Herein, we present a joint experimental (Raman scattering) and computational (DFT modelling) study on the high-pressure behaviour of PQ and PP molecular crystals. Our results indicate that compression up to 10 GPa (100 kbar) leads to considerable strengthening of the intermolecular hydrogen bond within the cyclic dimers. However, the intramolecular N–H···N interaction is either weakly affected by pressure, as witnessed in PQ, or weakened due to compression-induced distortions of the molecule, as was found for PP. Therefore, we propose that the compression of these systems should facilitate double proton transfer within the cyclic dimers of PQ and PP, while intramolecular transfer should either remain unaffected (for PQ) or weakened (for PP).
Lamellarin-inspired potent topoisomerase I inhibitors with the unprecedented benzo[g][1]benzopyrano[4,3-b]indol-6(13H)-one scaffold
Fukuda, Tsutomu,Nanjo, Yusuke,Fujimoto, Masahiro,Yoshida, Kenyu,Natsui, Yuko,Ishibashi, Fumito,Okazaki, Fumiyasu,To, Hideto,Iwao, Masatomo
, p. 265 - 277 (2019/01/04)
A new class of topoisomerase I inhibitors containing the unprecedented benzo[g][1]benzopyrano[4,3-b]indol-6(13H)-one (abbreviated as BBPI) ring system have been developed based on structure-activity relationship studies of the cytotoxic marine alkaloid la
Synthesis and evaluation of topoisomerase I inhibitors possessing the 5,13-dihydro-6H-benzo[6,7]indolo[3,2-c]-quinolin-6-one scaffold
Fukuda, Tsutomu,Matsuo, Yuri,Matsuoka, Fuyuki,Yoshioka, Naoki,Onodera, Gen,Kimura, Masanari,Ishibashi, Fumito,Iwao, Masatomo
, p. 1032 - 1052 (2019/07/31)
Novel topoisomerase I inhibitors possessing the 5,13-dihydro-6H-benzo[6,7]indolo[3,2-c]quinolin-6-one (BIQ) scaffold were designed and synthesized. This scaffold was constructed using sequential and regioselective functionalization of the pyrrole core thr
Stereochemistry and Mechanism of Undecylprodigiosin Oxidative Carbocyclization to Streptorubin B by the Rieske Oxygenase RedG
Withall, David M.,Haynes, Stuart W.,Challis, Gregory L.
supporting information, p. 7889 - 7897 (2015/07/02)
The prodiginines are a group of specialized metabolites that share a 4-methoxypyrrolyldipyrromethene core structure. Streptorubin B is a structurally remarkable member of the prodiginine group produced by Streptomyces coelicolor A3(2) and other actinobacteria. It is biosynthesized from undecylprodigiosin by an oxidative carbocyclization catalyzed by the Rieske oxygenase-like enzyme RedG. Undecylprodigiosin derives from the RedH-catalyzed condensation of 2-undecylpyrrole and 4-methoxy-2, 2′-bipyrrole-5-carboxaldehyde (MBC). To probe the mechanism of the RedG-catalyzed reaction, we synthesized 2-(5-pentoxypentyl)-pyrrole, an analogue of 2-undecylpyrrole with an oxygen atom next to the site of C-C bond formation, and fed it, along with synthetic MBC, to Streptomyces albus expressing redH and redG. This resulted in the production of the 6′-oxa analogue of undecylprodigiosin. In addition, a small amount of a derivative of this analogue lacking the n-pentyl group was produced, consistent with a RedG catalytic mechanism involving hydrogen abstraction from the alkyl chain of undecylprodigiosin prior to pyrrole functionalization. To investigate the stereochemistry of the RedG-catalyzed oxidative carbocyclization, [7′-2H](7′R)-2-undecylpyrrole and [7′-2H](7′S)-2-undecylpyrrole were synthesized and fed separately, along with MBC, to S. albus expressing redH and redG. Analysis of the extent of deuterium incorporation into the streptorubin B produced in these experiments showed that the pro-R hydrogen atom is abstracted from C-7′ of undecylprodigiosin and that the reaction proceeds with inversion of configuration at C-7′. This contrasts sharply with oxidative heterocyclization reactions catalyzed by other nonheme iron-dependent oxygenase-like enzymes, such as isopenicillin N synthase and clavaminate synthase, which proceed with retention of configuration at the carbon center undergoing functionalization. (Chemical Equation Presented).
Synthesis and switching the aromatic character of oxatriphyrins(2.1.1)
Pawlicki, Milosz,Hurej, Karolina,Szterenberg, Ludmila,Latos-Grazynski, Lechoslaw
supporting information, p. 2992 - 2996 (2014/04/03)
Triangularly shaped, contracted porphyrinoids belong to a group of molecules where the geometry significantly modifies the observed electronic properties. The need for a controllable, effective, and widely applicable approach to triphyrins drives extensive research towards macrocyclic materials that act as potential controlling motifs by switching their aromaticity. Two isomeric thiophene-fused triphyrins(2.1.1) were synthesized by applying an innovative approach. Spectroscopic techniques (NMR, UV/Vis) show that both macrocycles are aromatic and quantitatively convert into anti-aromatic structures after reduction with a zinc amalgam. The reduced forms were stabilized through boron(III) coordination, thereby allowing the observation of anti-aromatic 16 π delocalization within a contracted porphyrin. Going for a spin: The precisely crafted thiophene-fused oxatriphyrins(2.1.1) show an aromatic character consistent with 14 π or 18 π delocalization pathways. The aromaticity is strongly dependent on a thiophene incorporation mode and can be switched to anti-aromatic (16 π electrons) or non-aromatic by reduction with a zinc amalgam. Both reduced structures are stable as boron(III) complexes.
SLOW RELEASE OF ORGANOBORONIC ACIDS IN CROSS-COUPLING REACTIONS
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Page/Page column 41, 42-43, (2010/04/27)
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.
Trisoxazoline/Cu(II)-catalyzed asymmetric intramolecular Friedel-Crafts alkylation reaction of indoles
Zhou, Jiao-Long,Ye, Meng-Chun,Sun, Xiu-Li,Tang, Yong
supporting information; experimental part, p. 6877 - 6881 (2009/12/06)
Intramolecular Friedel-Crafts alkylation reaction of indoles catalyzed by trisoxazoline/copper(II) is described. This annulation provides an easy access to polycyclic indole derivatives with up to 90% ee in up to 99% yield.
