Palladium(II)-Catalyzed Intramolecular Diamination of Alkynes under Aerobic Oxidative Conditions: Catalytic Turnover of an Iodide Ion

Selective C(sp3 )-N Bond Cleavage of N,N-Dialkyl Tertiary Amines with the Loss of a Large Alkyl Group via an SN 1 Pathway

Polar disconnection of the C(sp³ )-N bond of N,N-dialkyl-substituted tertiary amines via ammonium species conventionally favored the loss of the smaller alkyl group by an S_N 2 displacement, while selective C(sp³ )-N bond cleavage by cutting off the larger alkyl group is still underdeveloped. Herein, we present a novel Pd⁰ -catalyzed [2+2+1] annulation, proceeding through an alkyne-directed palladacycle formation and consecutive diamination with a tertiary hydroxylamine by cleaving its N-O bond and one C(sp³ )-N bond, for the rapid assembly of tricyclic indoles in a single-step transformation. Noteworthy, experimental results indicated that large tert-butyl and benzyl groups were selectively cleaved via an S_N 1 pathway, in the presence of a smaller alkyl group (Me, Et, ⁱ Pr). Under the guidance of this new finding, tricyclic indoles bearing a removable alkyl group could be exclusively obtained by using a (α-methyl)benzyl/benzyl or tert-butyl/2-(methoxycarbonyl)ethyl mixed amino source.

Total Synthesis of (±)-Strictamine

The total synthesis of strictamine has been achieved in nine steps from a known enol triflate. Characteristic features of our approach included: a) creation of a C7 all-carbon quaternary stereocenter at an early synthetic stage; b) use of an N,N-dimethyl tertiary amine as a surrogate of the primary amine for the rapid build-up of a functionalized 2-azabicyclo[3,3,1]nonan-9-one skeleton (achieved by using a reaction sequence of α-bromination of the ketone, followed by a stereoconvergent intramolecular nucleophilic substitution reaction); and c) a late-stage construction of the indolenine unit.

Cu(I)-catalyzed sequential diamination and dehydrogenation of terminal olefins: a facile approach to imidazolinones

Diamination of olefins presents a powerful strategy to access vicinal diamines. During the last decade, metal-catalyzed diamination of olefins has received considerable attention. This study describes an efficient sequential diamination and dehydrogenation process of terminal olefins with CuBr as catalyst and di-tert-butyldiaziridinone as nitrogen source, providing a facile and viable approach to a variety of imidazolin-2-ones, which are important structural motifs present in various biologically active molecules.

Multicomponent assembly of highly substituted indoles by dual palladium-catalyzed coupling reactions

Highly substituted indoles were synthesized by a palladium-catalyzed reaction involving three independent components in a one-pot reaction. Two distinct palladium-catalyzed coupling reactions occur with a single catalytic system: a Buchwald-Hartwig reaction and an arene-alkene coupling. Quantum chemical computations provide insight into the mechanism of the latter coupling step.