The divergent total syntheses of complex natural products from a common intermediate have attracted enormous attention in the chemical community in the past few years because it can improve the efficiency of chemical synthesis. A number of powerful and unified strategies have been developed by emulating the natural biosynthesis or through innovative transformations. This review focuses on the total synthesis of natural products by applying divergent strategies and the literature covering from 2013 to June 2017. On the basis of where the diversity comes from, the examples are grouped into three parts and discussed in detail. In each group, the examples that synthesize natural products belonging to the same subfamily are put together to contrast with one another.

A concise total synthesis of lamellarins D (7 steps), H (7 steps), and R (5 steps) and ningalin B (5 steps) is achieved starting from the corresponding aldehydes and amines. The synthesis features three oxidative reactions as key steps in a biomimetic manner, involving an AgOAc-mediated oxidative coupling reaction to construct the pyrrole core, a Pb(OAc)(4)-induced oxidative cyclization to form the lactone, and Kita's oxidation reaction to form the pyrrole-arene C-C bond.

An efficient synthesis of functionalized 3-alkyl-3-cyanomethyl-2-oxindole 1 by a palladium-catalyzed domino Heck-cyanation reaction has been developed. Reaction of ortho-iodoanilide 5 with potassium ferro(II)cyanide, K(4)[Fe(CN)(6)], dissolved in DMF in the presence of palladium acetate and sodium carbonate afforded oxindole 1 in good to excellent yields. An enantioselective domino Heck-cyanation process has been developed for the first time using (S)-DIFLUORPHOS as a chiral supporting ligand, and an enantioselectivity of up to 79 % ee in the enantiomerically enriched oxindole was obtained under optimized conditions. A concise total synthesis of esermethole and physostigmine, powerful inhibitors of acetyl- and butyryl-cholinesterase, is documented.

A phytochemical investigation of aquilariae lignum resinatum, the resinous wood of Aquilaria sinensis (Lour.) Gilg, led to the isolation of nine new 2‐(2‐phenylethyl)chromone derivatives, aquilarones A–I (1–9), together with two known analogues (10 and 11). Their structures were elucidated by extensive spectroscopic analyses, including UV, IR, NMR, and electronic circular dichroism (ECD) data, as well as by chemical methods. The absolute configuration of aquilarone A (1) was confirmed by single‐crystal X‐ray diffraction analysis of its acetonide derivative 1a. All the compounds exhibited significant inhibition of the nitric oxide production in RAW 264.7 cells, with IC50 values in the range of 5.12–22.26 μM. In addition, an HPLC–UV comparison analysis of the resinous wood and resin‐free wood is also included.

The first Pd-catalyzed method for direct olefination at the C4 position of tryptophan derivatives has been developed via C-H activation to prepare 4-substituted tryptophans, which could be used for the synthesis of many hemiterpenoid indole alkaloids. This reaction proceeds under mild reaction conditions and with exceptional tolerance to a variety of functional groups. Furthermore, the efficiency of this method is demonstrated by the rapid and biomimetic synthesis of clavicipitic acid.

Covering: 2000 to 2017Ergot alkaloids are among the most important pharmaceuticals and natural toxins. Significant progress has been achieved in recent years on the research of ergot alkaloids. In this review, we re-introduced the history of ergot alkaloids. Meanwhile, we summarized all the natural products and semi-synthetic derivatives of ergot alkaloids. We also briefly described the biosynthesis and semi-synthesis of ergot alkaloid drugs from raw materials obtained by fermentation. Moreover, we reviewed the advances that have been made in the total synthesis of ergot alkaloids since 2000.

This review describes the synthetic approaches to natural products containing the 2,3-dihydrobenzofuran (2,3-DHB) skeleton.

One-pot synthesis of indoles by a palladium-catalyzed annulation of ortho-haloanilines and aldehydes has been developed. Coupling of ortho-iodoaniline with aldehyde is realized under mild ligandless conditions [Pd(OAc)2, DABCO, DMF, 85 degrees C], whereas X-Phos is found to be the ligand of choice for coupling reactions involving ortho-chloroanilines/ortho-bromoanilines and aldehydes. A variety of ortho-haloanilines with different electronic properties are suitable substrates, and aldehydes including chiral ones participated in this reaction without racemization. Coupling of (S)-2-N,N-di-tert-butoxycarbonyl-5-oxopentanoate, derived from L-glutamic acid, with ortho-haloanilines provides a rapid access to the ring-A-substituted tryptophans in good to excellent yields.