An asymmetric α-amination of β-keto esters with azodicarboxylate in the presence of a guanidine-bisurea bifunctional organocatalyst was investigated. The α-amination products were obtained in up to 99% yield with up to 94% ee.

Mn(III)-based oxidative free-radical cyclization of an unsaturated beta-keto ester containing a pyridine ring as radical trap has been studied. This intramolecular reaction of nucleophilic carbon-centered radicals with the pyridine ring leads to the stereospecific construction of a tetracyclic compound in which five chiral centers are created in one pot. This synthetic approach represents the f...

trans-3-Hydroxy-nn-proline-3,4-3H was synthesized by reduction of N-carbobenzoxy-3-keto-DLproline methyl ester with NaBH4 (4). Uniformly labeled n-proline-r4C was obtained from New England Nuclear Corporation. Uniformly labeled 4-hydroxy-r.-prolineJ4C was generously donated to us by Dr. Chozo Mitoma. Seven-day-old chick embryos were obtained from the Duckworth Hatchery (Elkridge, Maryland) and ...

trans-3-Hydroxy-nn-proline-3,4-3H was synthesized by reduction of N-carbobenzoxy-3-keto-DLproline methyl ester with NaBH4 (4). Uniformly labeled n-proline-r4C was obtained from New England Nuclear Corporation. Uniformly labeled 4-hydroxy-r.-prolineJ4C was generously donated to us by Dr. Chozo Mitoma. Seven-day-old chick embryos were obtained from the Duckworth Hatchery (Elkridge, Maryland) and ...

The first examples of Cu-catalyzed γ-selective allylic alkenylation using organozinc reagents are reported. (E)-Alkenylzinc iodides were prepared by Fe-catalyzed reductive coupling of terminal arylalkynes with alkyl iodides. In the presence of a copper catalyst, these reagents reacted with allylic bromides derived from Morita-Baylis-Hillman alcohols to give 1,4-dienes in high yields. The reacti...

An efficient method for molecular iodine catalyzed decarboxylative substitution of β-keto acids with benzylic alcohols under mild conditions has been described and valuable α-functionalized ketones were obtained in good to excellent yields.