Mio Matsumura

Design and synthesis of 4-benzyl-1-(2H)-phthalazinone derivatives as novel androgen receptor antagonists.

The androgen receptor (AR) plays important roles in multiple physiological functions, including differentiation, growth, and maintenance of male reproductive organs, and also has effects on hair and skin. In this paper, we report the synthesis of nonsteroidal AR antagonists having a 4-benzyl-1-(2H)-phthalazinone skeleton. Among the synthesized compounds, 11c with two ortho-substituents on the phenyl group potently inhibited SC-3 cell proliferation (IC50: 0.18 μM) and showed high wt AR-binding affinity (IC50: 10.9 μM), comparable to that of hydroxyflutamide (3). Compound 11c also inhibited proliferation of LNCaP cells containing T877A-mutated AR. Docking study of 11c with the AR ligand-binding domain indicated that the benzyl group is important for the antagonism. These phthalazinone derivatives may be useful for investigating potential clinical applications of AR antagonists.

Copper-catalyzed [3 + 2] cycloaddition of (phenylethynyl)di-p-tolylstibane with organic azides

Summary Trisubstituted 5-stibano-1H-1,2,3-triazoles were synthesized in moderate to excellent yields by the Cu-catalyzed [3 + 2] cycloaddition of a ethynylstibane with organic azides in the presence of CuBr (5 mol %) under aerobic conditions. The reaction of 5-stibanotriazole with HCl, I2, and NOBF4 afforded 1-benzyl-4-phenyltriazole, 1-benzyl-5-iodo-4-phenyltriazole, and a pentavalent organoantimony compound, respectively.

Calix[3]amide-based anion receptors: high affinity for fluoride ions and a twisted binding model

Tris-phenylurea-substituted calix[3]amides (3a, 3b) and tris-phenylthiourea-substituted calix[3]amides (4a, 4b) were synthesised by the reaction of amine with isocyanates and thioisocyanate, respectively. Single crystal X-ray analysis revealed that the cyclic trimers adopt a syn conformation with all of the urea groups on the same side. The binding affinities of these compounds towards anions were measured using 1H NMR titrations in DMF-d 7 , DMSO-d 6 or CDCl3. Each receptor was observed to bind halogen anions in a 1:1 stoichiometry, exclusively through hydrogen bonding, and the anion selectivity was in the order F− > Cl− ≫Br− > I− . DFT calculations revealed that the fluoride anion is anchored in the centre of the six N–H hydrogen atoms of 3a through H···F interactions.

Synthesis, antitumor activity, and cytotoxicity of 4-substituted 1-benzyl-5-diphenylstibano-1H-1,2,3-triazoles

Trisubstituted 5-organostibano-1H-1,2,3-triazoles (3a-f) were synthesized by the Cu-catalyzed azide-alkyne cycloaddition of various ethynylstibanes (1) with benzylazide (2) in the presence of CuBr (5 mol%) under aerobic conditions. The reaction of 5-stibanotriazoles with HCl afforded C5-unsubstituted 1,2,3-triazoles (4a-f). The antitumor activity of trisubstituted 5-organostibano-1H-1,2,3-triazoles (3a-f) and their 5-unsubstituted 1,2,3-triazoles (4a-f) were evaluated in several tumor cell lines. All 5-stibanotriazoles (3a-f) exerted an excellent antitumor activity. On the contrary, 5-unsubstituted 1,2,3-triazoles (4a-f) without a diphenylantimony group in the molecule exhibited very low antitumor activity compared with 5-stibanotriazoles (3a-f). In compounds of both the series, the substituted 4-butyl group appeared to decrease antitumor activity. However, results suggested that organometal (antimony) in the molecule was required for greater antitumor activity. In addition, all 5-stibanotriazoles (3a-f), but not all 5-unsubstituted 1,2,3-triazoles (4a-f), exhibited cytotoxicity in normal vascular endothelial cells derived from bovine aorta. Among the compounds (3b-e) that exhibited excellent antitumor activity, those with 4-methylphenyl (3b) and 1-cyclohexenyl (3e) showed relatively low cytotoxicity to vascular endothelial cells. Together, these results suggest that trisubstituted 5-organostibano-1H-1,2,3-triazoles, including compounds 3b and 3e, may serve as potential anticancer therapeutic drugs in the future.

Pd-catalyzed P-arylation of triarylantimony dicarboxylates with dialkyl H-phosphites without a base: synthesis of arylphosphonates.

The reaction of triarylantimony diacetates [Ar3Sb(OAc)2] with dialkyl H-phosphites [H-PO(OR)2] in the presence of a Pd(PPh3)4 (5 mol%) catalyst led to the formation of arylphosphonates in moderate to excellent yield under base-free conditions. This reaction is the first example of carbon-phosphorus bond formation by using an organoantimony compound as a pseudo-halide.

Microwave-Assisted Debromination of α-Bromoketones with Triarylstibanes in Water

Several α-bromoarylketones were reacted with triarylstibanes under microwave irradiation in water to obtain the corresponding debrominated ketones. Under similar reaction conditions, 1,2-elimination of vic-dibromides in water afforded the corresponding E-olefins. This reaction is the first example of organoantimony compounds utilized for organic transformation in water.

Synthesis and photophysical properties of novel benzophospholo[3,2-b]indole derivatives

The parent benzophospholo[3,2-b]indole was prepared by the reaction of dichlorophenylphosphine with a dilithium intermediate, which was prepared in two steps from 2-ethynyl-N,N-dimethylaniline. Using the obtained benzophosphole-fused indole as a common starting material, simple modifications were carried out at the phosphorus center of the phosphole, synthesizing various functionalized analogs. The X-ray structure analysis of trivalent phosphole and phosphine oxide showed that the fused tetracyclic moieties are planar. The benzophosphole-fused indoles, such as phosphine oxide, phospholium salt, and borane complex, exhibited strong photoluminescence in dichloromethane (Φ = 67–75%).