Regioselective addition of 1,3-dicarbonyl dianion to N-sulfonyl aldimines: an expedient route to N-sulfonyl piperidines and N-sulfonyl azetidines

Organocatalytic Enantioselective γ-Position-Selective Mannich Reactions of β-Ketocarbonyl Derivatives

Catalytic asymmetric Mannich reactions of β-ketocarbonyl derivatives (such as β-ketoesters and (2-oxopropyl)phosphonate), resulting in the formation of a C–C bond at the γ-position of the β-ketocarbonyl derivatives with high enantioselectivities, are reported. The bond formation at the α-position of the β-ketoester was reversible, and the γ-position-reacted product δ-amino β-ketoester derivative was kinetically formed and was stable. The dynamic kinetic process was key for the direct access to the γ-position-reacted products from β-ketocarbonyls under catalytic conditions.

One pot oxidative N–S bond formation to access 2-sulfenylimine chromenes

Synthesis of 2-sulfenylimine chromene compounds is accomplished in a one-pot, catalyst-free, five-component reaction in toluene. When aniline was employed as nucleophile formation of hexahydrobenzofuran-2-N-phenyl carboxamide was observed. Excellent yields, simple reaction conditions high compatibility are the advantages of this protocol.

Stereoselective synthesis of activated 2-arylazetidines via imino-aldol reaction

A highly stereoselective synthesis ofN-sulfinyl andN-sulfonyl azetidines have been developed involving imino-aldol reaction of ester enolates with aldimines.

Regioselective Addition of 1,3-Dicarbonyl Dianions to Carbonyl Compounds: One Pot Lactonization and Ketalization of δ-Hydroxy-β-keto Esters to Protected Pyrone Derivatives

A simple and efficient strategy for the synthesis of 6-substituted-2-pyrone derivatives, by BF3·OEt2 mediated one pot cyclization and keto-protection of δ-hydroxy-β-keto esters, obtained via regioselective addition of 1,3-dicarbonyl dianion of ethyl acetoacetate to aldehydes and ketones is described.

Structure-activity relationship study of first selective inhibitor of excitatory amino acid transporter subtype 1: 2-Amino-4-(4-methoxyphenyl)-7-(naphthalen-1-yl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (UCPH-101)

The excitatory amino acid transporters (EAATs) are expressed throughout the central nervous system, where they are responsible for the reuptake of the excitatory neurotransmitter (S)-glutamate (Glu). (1) Recently, we have reported the discovery of the first subtype selective EAAT1 inhibitor 2-amino-4-(4-methoxyphenyl)-7-(naphthalen-1-yl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile (UCPH-101) (1b) and presented an introductory structure-activity relationship (SAR) study. (2) Here, we present a detailed SAR by the design, synthesis, and pharmacological evaluation of analogues 1g-1t. By comparison of potencies of 1b, 1h, and 1i versus 1j, it is evident that potency is largely influenced by the chemical nature of the R(1) substituent. The study also demonstrates that any chemical change of the functional groups or a change to the parental scaffold results in the complete loss of inhibitory activity of the compounds at EAAT1. Finally, a bioavailability study of UCPH-101 determined the half-life to be 30 min in serum (rats) but also that it was not able to penetrate the blood-brain barrier to any significant degree.