Antitumor activity of selenopsammaplin A analog (SPA-10091-HCl) via histone methyltransferase DOT1L degradation and apoptosis induction in castration-resistant prostate cancer cells.

Castrate-resistant prostate cancer (CRPC) is one of the most difficult cancers in men and is characterized by a poor prognosis and a high risk of metastasis. The overexpression of the disruptor of telomeric silencing 1-like (DOT1L), which is a specific methyltransferase for histone H3 at lysine residue 79 (H3K79), has been related to poor outcomes in patients with CRPC. Therefore, targeting DOT1L is considered a potential therapeutic approach to overcome the significant medical challenges of CRPC.

Enantioselective Michael addition of 3-hydroxy-2-pyridone to nitroolefins using cinchona-derived bifunctional organocatalysts.

Despite the extensive use of N-heteroarenes in pharmaceuticals and natural products, efficient methods for selective alkylation at the C-4 position of 2-pyridone are scarce. We developed an enantioselective Michael addition of 3-hydroxy-2-pyridone to nitroolefins at the C-4 position using cinchona-derived bifunctional squaramide organocatalysts, achieving up to 95% yield and >99% ee. This selectivity is driven by the bifunctional organocatalysts' hydrogen bonding interactions with 3-hydroxy-2-pyridone and nitroolefins under mild conditions.

Enantioselective Synthesis of ()-Sitagliptin via Phase-Transfer Catalytic aza-Michael Addition.

The highly enantioselective synthesis of ()-sitagliptin has been achieved through a series of key steps, including the aza-Michael addition and Baeyer-Villiger oxidation. The enantioselective aza-Michael addition involved the reaction of -butyl β-naphthylmethoxycarbamate with ()-1-(4-methoxyphenyl)-4-(2,4,5-trifluorophenyl)but-2-en-1-one, utilizing a quinine-derived C(9)-urea ammonium catalyst under phase-transfer catalytic conditions. The aza-Michael addition successfully introduced chirality to the amine in ()-sitagliptin with 96% ee.

Asymmetric Phase-Transfer Catalytic aza-Michael Addition to Cyclic Enone: Highly Enantioselective and Diastereoselective Synthesis of Cyclic 1,3-Aminoalcohols.

The highly enantioselective aza-Michael reaction of -butyl β-naphthylmethoxycarbamate to cyclic enones has been accomplished by using a new alkaloid derived C(9)-urea ammonium catalyst under phase-transfer catalysis conditions with up to 98% ee at 0 °C. The resulting aza-Michael adducts can be converted to versatile intermediates by selective deprotection and the cyclic 1,3-aminoalcohols by diastereoselective reduction with up to 32:1, which have been widely used as important pharmacophores in pharmaceutical development.

Synthesis and biological activity of selenopsammaplin A and its analogues as antitumor agents with DOT1L inhibitory activity.

Disruptor of telomeric silencing-1 like (DOT1L) is a histone H3 methyltransferase which specifically catalyzes the methylation of histone H3 lysine-79 residue. Recent findings demonstrate that DOT1L is abnormally overexpressed and the upregulated DOT1L evokes the proliferation and metastasis in human breast cancer cells. Therefore, the DOT1L inhibitor is considered a promising strategy to treat breast cancers.

Enantioselective Total Synthesis of Alkaloids: (+)-Nitramine, (+)-Isonitramine, (-)-Isonitramine, and (-)-Sibirine via Asymmetric Phase-Transfer Catalytic α-Allylations of α-Carboxylactams.

Many optically active 2-azaspirocyclic structures have frequently been found in biologically active natural products. In particular, alkaloids, (+)-nitramine, (+)-isonitramine, (-)-isonitramine, and (-)-sibirine, have stereogenicity on their quaternary carbon of the 2-azaspiro[5,5]undecane-7-ol structure. To synthesize alkaloids, we developed a new enantioselective synthetic method for chiral α-quaternary lactams via the α-alkylation of α--butoxycarbonyl lactams.

Enantioselective Synthesis of (+)-Coerulescine by a Phase-Transfer Catalytic Allylation of Diphenylmethyl -Butyl α-(2-Nitrophenyl)Malonate.

A 7-step enantioselective synthetic method for preparing (S)(+)-coerulescine is reported through the use of diphenylmethyl tert-butyl α-(2-nitrophenyl)malonate (16% overall yield, >99% ee). Allylation is the key step under phase-transfer catalytic conditions (86% ee). This synthetic method can be used as a practical route for the synthesis of various derivatives of (S)(+)-coerulescine for analyzing its structure-activity relationships against its biological activities.