Cl 2 ] 1a-l (HC _ N = arylpyridines) and a PEG-linked complex 1m were synthesized. Complexes 1a-m are effective in catalyzing the synthesis of propargylic amines, chiral allenes and isoxazoles. Six-membered ring cyclometallated goldA C H T U N G T R E N N U N G (III) complexes 1f-l exhibited higher catalytic activity than five-membered ring cyclometallated goldA C H T U N G T R E N N U N G (III) complexes 1a-e. The diastereoselectivity of propargylic amines could be tuned by using chiral aldehyde and/ or amine substrates. Excellent enantioselectivities (90-98% ee) were achieved in chiral allene synthesis. Chiral allene racemization could be minimized by using 1f as catalyst. The PEG-linked catalyst 1m is the most catalytically active towards synthesis of propargylic amines, in which case a product turnover of 900 was achieved. Moreover, 1m could be repeatedly used for 12 reaction cycles, leading to an overall turnover number of 872.

Three steroidal saponins, including one new and two known compounds, were isolated from the rhizomes of Paris polyphylla Smith. One- and two-dimensional NMR, LC-MS, and interpretation of hydrolytic cleavage experiments led to the identification of the structure of the new saponin as ( 25R)-spirost-5-ene-3 beta,17 alpha-diol (pennogenin) 3- O-{ O- alpha- L-rhamnopyranosyl-(1-->2)- O-[ O- beta-xylopyranosyl-(1-->5)- alpha- L-arabinofuranosyl-(1-->4)]- beta- D-glucopyranoside}. The isolated saponins were evaluated for their antifungal activity against Cladosporium cladosporioides and Candida species and showed comparable activity to chemicals used in some commercial products.

Javanicunines A-B and 9-deoxy-PF1233s A-B belong to a family of natural diketomorpholines with a unique isopropenyl group at C-10b or C-5a and a hydroxyl group at C-11a or C-10b. We herein reported the first total synthesis of javanicunines A-B and 9-deoxy-PF1233s A-B. Pivotal features of the synthesis included a nucleophilic substitution reaction, followed by a Davis’ oxaziridine oxidation to assemble javanicunines A-B, and a chemoselective and stereoselective oxidation with Murray’s reagent to install the requisite C-10b hydroxyl group in 9-deoxy-PF1233s A-B. The present synthesis also established the absolute configuration of javanicunine B.

Cancer is a leading cause of mortality in the world and metastasis is to blame. Invasion is the initial step of metastasis. Therapies targeting epithelial-mesenchymal transition (EMT), cancer stem cells (CSCs) and signal transducer and activator of transcription 3 (STAT3) signaling pathways can reduce stemness of cancer cells and thus inhibit cancer invasion. A large number of anti-cancer naphthoquinones (NQs) can target cancer invasion by acting on EMT, CSCs and STAT3 signaling. Furano-naphthoquinones (FNQs) belong to a class of NQ derivatives commonly characterized by a naphthoquinone fused with a furano ring. A study indicated that the corporation of the furano ring improved the anticancer potency as compared to the other classes of NQs. BBI608, a natural FNQ, which can be found in the woods or barks of several Tabebuia species, has entered phases I and II clinical trials. It has been regarded as a potential candidate for new-generation lead compound acting directly on CSCs to overcome the chemotherapy resistance. Apart from the natural plant sources, there are a number of synthetic FNQ derivatives that are effective in reducing stemness of cancer cells and thus are anti-invasive. In this review, the anti-invasion mechanisms of NQs and the more powerful FNQs, together with their natural origins, synthetic derivatives as well as their synthetic routes are discussed.