The synthesis of fluorinated compounds as well the use these products building blocks for preparation complex molecules are fast growing research areas. Herein we highlight recent progress in activation allylic and benzylic C–F bonds functionalized molecules. SN2′ reactions difluoro trifluoro transition-metal-catalyzed (nickel, palladium, platinum copper) processes described. bond 3-fluoropropenes was achieved with platinum- or organocatalysis. Benzylic realized magnesium by deprotonation...

A highly efficient strategy enabled the asymmetric total synthesis of 15 antifeedant leucosceptroid natural products. The advanced tricyclic core, available in gram quantity, served as pivotal intermediate for preparation norleucosceptroids B, C, F, and G leucosceptroids A, G, I, J, L, M. Additionally, bioinspired oxidative transformation to K, O, P using singlet oxygen supports hypothesis that B are most likely biogenetic precursors all other members this product family.

Crossing swords: Two novel approaches to the antibiotic kendomycin are described. Salient features complex Claisen–Ireland rearrangements and macrocyclizations by ring-closing metathesis (RCM) a photo-Fries rearrangement (see retrosynthesis scheme). Detailed facts of importance specialist readers published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted authors. Please note: The publisher is responsible for content...

We present a bioinspired late-stage C–H oxidation of the ent-trachylobane natural product mitrephorone B to A. The realization this unprecedented transformation was accomplished by either an iron-catalyzed or electrochemical and enabled access densely substituted oxetane in one step. Formation C, which is lacking central unit but features keto-function at C2, not formed under these conditions.

We report the first asymmetric total synthesis of maleidrides glauconic and glaucanic acid. Key transformations include syn -selective Evans aldol a diastereoselective intramolecular alkylation to construct nine-membered ring.

We report the total synthesis of dactyloquinone A and spiroetherone from a meroterpenoid scaffold obtained by deconjugative alkylation Wieland–Miescher type ketone. For A, we employed an intramolecular hydrofunction-alisation internal trisubstituted alkene with quinone monoacetal via metal-hydride hydrogen atom transfer (MHAT) process to form key C–O bond. relied on stereospecific quinol-spiroenedione rearrangement. The initially postulated structure was first synthesized, but found be...

Methyltransferases are a broad class of enzymes that catalyse the transfer methyl groups onto wide variety substrates and functionalities. In their most striking variant, bifunctional methyltransferase-cyclases both group alkenes induce cyclization (methylcyclization). Although recent years have seen substantial advances in methylation alkenes, especially hydromethylation, reactivity demonstrated by nature has yet to be developed into synthetically viable method. Here we report...

Abstract The first asymmetric total synthesis of the antifeedant terpenoids (+)‐norleucosceptroid A, (−)‐norleucosceptroid B, and (−)‐leucosceptroid K has been accomplished. This highly concise synthetic route was guided by our efforts to develop a platform for collective whole family natural products. features Hauser–Kraus‐type annulation followed an unprecedented, efficient intramolecular dilactol aldol‐type condensation reaction produce 5,6,5 skeleton. developed proceeds norleucosceptroid...

The development of a sequential O–H/C–H bond functionalization phenols initiated by the cationic gold(I)-catalyzed cyclization 1-bromo-1,5-enynes to produce (2-bromocyclopent-2-en-1-yl)phenols is reported. This unprecedented domino transformation efficiently proceeds under mild conditions (5 mol % (t-Bu)3PAuNTf2, CH2Cl2, 0–23 °C) via an intermediate aryl alkyl ether which collapses at ambient temperature undergo 1,2-hydride shift followed C–H insertion phenol.

Abstract We report the synthesis of orthogonally functionalized naphthalenes from simple, commercially available indanones in four steps. The developed method proceeds through a two‐step process that features thermally induced fragmentation cyclopropane indanone with simultaneous 1,2‐chloride shift. Migration chloride substituent occurs regioselective manner to preferentially afford para ‐chloronaphthol substitution pattern. obtained naphthols are versatile building blocks can be selectively...

Many natural products comprising a nine-membered carbocyclic core structure exhibit interesting biological effects. However, only minority have succumbed to their synthesis in the past. The of functionalized carbocycles still remains challenging goal for synthetic chemists, mainly due high ring strain. Different strategies overcome unfavorable enthalpic and entropic factors associated with formation are highlighted this Concept article. presented methods classified into two different...

Despite the many methods available for synthesis of furans, few remain that allow custom-made assembly fully substituted furans. Here we report a powerful protocol to rapidly construct tetrasubstituted, orthogonally functionalized furans under mild reaction conditions. The developed method involves regioselective ring-opening readily 2,5-dihydrothiophenes followed by an oxidative cyclization provide heterocycle. selective oxidation at sulfur is promoted N-chlorosuccinimide as inexpensive...

The first asymmetric total synthesis of the Xenia diterpenoid waixenicin A, a potent and highly selective TRPM7 inhibitor, is reported. characteristic trans-fused oxabicyclo[7.4.0]tridecane ring system was constructed via diastereoselective conjugate addition/trapping sequence, followed by an intramolecular alkylation to forge 9-membered ring. While β-keto sulfone motif enabled efficient ring-closure, subsequent radical desulfonylation suffered from (E)/(Z)-isomerization C7/C8-alkene....

The first total syntheses of the novel 3,5,5,7-sesquiterpenoids (+)-Echinopine A (1) and B (2) were achieved. Thereby proposed structures confirmed, absolute stereochemistry was determined. key features are stereoselective installation vinyl-moiety on concave side bicyclo[3.3.0]octane core via Myers' [3,3]-sigmatropic rearrangement, finding that substituent C7 position next to ketone can be epimerized desired face under basic conditions, (3) closure highly strained seven-membered ring RCM,...

Stachyflin, aureol, smenoqualone, strongylin A, and cyclosmenospongine belong to a family of tetracyclic meroterpenoids, which, by nature their unique molecular structures various biological properties, have attracted synthetic medicinal chemists alike. Despite obvious biosynthetic relationship, only scattered reports on the synthesis investigation individual meroterpenoids appeared so far. Herein, we report highly modular strategy that enabled each these natural products 15 non-natural...

Described is the development of a highly efficient 2π disrotatory ring-opening aromatization sequence using bicyclo[3.1.0]hexan-2-ones. This unprecedented transformation efficiently proceeds under thermal conditions and allows facile construction uniquely substituted polyfunctionalized benzoates. In presence either amines or alcohols formation anilines ethers, respectively, achieved. Additionally, utility this method was demonstrated in short synthesis sekikaic acid methyl ester.

Abstract The cationic cyclization of polyenes constitutes a powerful and elegant transformation, which has been utilized by nature's biosynthetic machinery for the construction complex polycyclic terpenoids. Previous studies chemists to mimic this in laboratory were limited different modes activation using biosynthetic‐like precursors, accommodate only simple methyl‐derived substituents. Here we describe development an unprecedented highly efficient polyene aryl enol ether containing...

We report a full account on the development of unique cationic polyene cyclization for total synthesis tetracyclic meroterpenoid (-)-cyclosmenospongine. A highly convergent three-component coupling strategy enabled rapid access to individual precursors that were tested their reactivity. The successful transformation generates three rings and sets four consecutive stereocenters in single operation proceeding efficient manner give exclusively trans-decalin framework. In addition, we found enol...

Salimabromide is an antibiotic polyketide that was previously isolated from the obligate marine myxobacterium Enhygromyxa salina, and its densely functionalized conformationally rigid tetracyclic framework unprecedented in nature. Herein we report first chemical synthesis of target structure by employing a series well-orchestrated, robust transformations, highlighted acid-promoted, powerful Wagner–Meerwein rearrangement/Friedel–Crafts cyclization sequence to forge two adjacent quaternary...

Two convergent total syntheses of the ansa-polyketide (-)-kendomycin (1) are described. The benefit from use readily available and cheap starting materials. Highly complex diastereoselective Claisen-Ireland rearrangements were used to introduce (E)-double bond C16-Me group. ring closure strained ansa macrocycle was achieved by ring-closing metathesis a highly efficient combination macrolactonization photo-Fries reaction. A protecting group free endgame via an unstable o-quinone is presented....