Synthesis of dibenzoxepine lactams via a Cu-catalyzed one-pot etherification/aldol condensation cascade reaction: application toward the total synthesis of aristoyagonine.

A general synthesis of dibenzoxepine lactams has been developed using a one-pot Cu-catalyzed etherification/aldol condensation cascade reaction. The reaction of 4-hydroxyisoindolin-1-one with a wide range of 2-bromobenzaldehydes in the presence of a copper catalyst provided various aristoyagonine derivatives in good yields.

One-pot transition-metal-free synthesis of dibenzo[b,f]oxepins from 2-halobenzaldehydes.

A one-pot transition-metal-free, base-mediated synthesis of dibenzo[b,f]oxepins was developed. The reaction of 2-halobenzaldehydes with (2-hydroxyphenyl)acetonitriles proceeds via a sequential aldol condensation and intramolecular ether formation reaction in the presence of Cs(2)CO(3) and molecular sieves in toluene.

Total synthesis of laetevirenol A.

The first complete synthesis of laetevirenol A was performed in nine steps via intramolecular Friedel-Crafts alkylation in a trans-selective manner. The key phenanthrene intermediate was synthesized by a one-pot Suzuki-Miyaura coupling and an aldol condensation cascade reaction.

Stereoselective palladium-catalyzed α-arylation of 3-aryl-1-indanones: an asymmetric synthesis of (+)-pauciflorol F.

Highly stereoselective, palladium-catalyzed α-arylation reactions of 3-aryl-1-indanones with aryl bromides are described. The use of sodium tert-butoxide as a base in this process is required to elevate the efficiencies and stereoselectivities of these reactions. The new methodology was successfully applied to a highly efficient route for the asymmetric synthesis of (+)-pauciflorol F.

Synthesis of aristolactam analogues and evaluation of their antitumor activity.

A series of natural aristolactams and their analogues have been prepared and evaluated for antitumor activity against human cancer cells, including multi-drug resistant cell lines. Naturally occurring aristolactams, such as aristolactam BII (cepharanone B), aristolactam BIII, aristolactam FI (piperolactam A), N-methyl piperolactam A, and sauristolactam showed moderate antitumor activities in selected cell lines. However, several synthetic aristolactam derivatives exhibited potent antitumor activities against a broad array of cancer cell lines with GI(50) values in the submicromolar range.

Efficient synthesis of dibenzo[a,c]cyclohepten-5-ones via a sequential Suzuki-Miyaura coupling and aldol condensation reaction.

A common strategy for the synthesis of a 7-membered-ring system with a Suzuki-Miyaura coupling followed by an acid/base-promoted intramolecular aldol condensation reaction has been developed. The reaction of 2'-bromoacetophenones with 2-formylphenylboronic acids in the presence of Pd(OAc)(2) and CataCXium PIntB L8 efficiently provided biaryl compounds, which were transformed to a wide array of dibenzo[a,c]cyclohepten-5-ones in excellent yields by a sequential treatment with p-TsOH, followed by 10% aq NaOH.