Discovery of a potent, orally available furopyridine derivative as a novel selective bromodomain and extra-terminal domain (BET)-first bromodomain (BD1) inhibitor.

We explored novel immunosuppressive agents with immune tolerance using a phenotypic drug discovery strategy, focusing on costimulatory molecules in T cells, and obtained triazolothienodiazepine derivatives. Their mechanism of action is to inhibit the bromodomain and extra-terminal domain (BET) family, as we have previously reported. Selective inhibition of the first bromodomain (BD1) of the BET family is expected to exert antitumor and immunosuppressive effects, similar to BET inhibitors. This study identified furopyridine derivatives 7 and 8 with high BD1 inhibitory activity and high selectivity over BD2. Compound 7 was found to be orally bioavailable and exhibited anti-inflammatory activity in a lipopolysaccharide-induced model.

Discovery of a potent orally available pyrazolopyridone derivative as a novel selective bromodomain and extra-terminal domain (BET)-first bromodomain (BD1) inhibitor.

Clinical studies have shown that inhibitors of bromodomain and extra-terminal domain (BET) proteins, particularly BRD4, have antitumor activity and efficacy. The BET protein has two domains, BD1 and BD2, and we previously focused on BD1 and reported orally bioavailable BD1-selective inhibitors. In this study, we obtained a BD1 inhibitor, a more potent and highly selective pyrazolopyridone derivative 13a, and confirmed its in vivo efficacy.

Copper(I)-Catalyzed Stereodivergent Propargylation of N-Acetyl Mannosamine for Protecting Group Minimal Synthesis of C3-Substituted Sialic Acids.

Copper(I)-catalyzed stereodivergent nucleophilic propargylation at the anomeric carbon of unprotected N-acetyl mannosamine was developed using 3-substituted allenylboronates as a nucleophile. The homopropargylic alcohol products contained two contiguous stereocenters, and two stereoisomers out of the four possible isomers were selectively obtained in a catalyst-controlled manner by applying either basic conditions: a MesCu/(R,R,R)-Ph-SKP catalyst with a B(OiPr)3 additive or acidic conditions: a CuBF4/(S,S,S)-Ph-SKP catalyst with an MeB(OiPr)2 additive. Mechanistic studies suggested the presence of distinct active nucleophilic species depending on the conditions: an allenylcopper species under the basic conditions or an allenylboronate activated by the Lewis acidic copper catalyst under the acidic conditions. The propargylation products were concisely transformed into C3-substituted sialic acids in two steps without the use of protecting groups.

Boron-Catalyzed Carboxylic Acid-Selective Aldol Reaction with Trifluoromethyl Ketones.

A catalytic carboxylic acid-selective aldol reaction with trifluoromethyl ketones was developed. Reversible and selective covalent bond formation between a boron catalyst and a carboxylic acid is key to realizing the unprecedented catalytic aldol reaction of simple carboxylic acids. The reaction proceeded chemoselectively at the α-position of carboxylic acid even in the presence of ketone, ester, or amide functional groups in the donor substrates. The chemoselectivity is beneficial for late-stage derivatizations of biologically relevant compounds, as demonstrated by the conversion of indomethacin and triacetylcholic acid.