In this Thematic Series, selected examples of metal- and organic-compound-promoted chemical processes that render the preparation of architecturally complex natural products, natural-product subdomains, or natural-product-like scaffolds, are presented. These illustrative synthetic studies are intended to showcase the most recent developments, at the same time highlight the state-of-the-art and current limitations, and in doing so set the path for the future. It is our great anticipation that this Thematic Series will instigate and inspire further investigations in this field, and challenge the existing technologies and our current mindset in target-oriented synthetic design.
See also the Thematic Series:
Organocatalysis
Copper catalysis in organic synthesis
Gold catalysis for organic synthesis II
Graphical Abstract
Scheme 1: Structure of ryanodine and the Diels–Alder reactions for construction of the potential intermediate...
Scheme 2: Asymmetric synthesis of 7 and determination of the absolute configuration at C4 of 15 by the modifi...
Scheme 3: Generation of 17 through the 6π-electrocyclic reaction and the Diels–Alder reaction.
Scheme 4: Rationale of the stereoselectivity of the Diels–Alder reaction.
Scheme 5: Synthesis of C2-symmetric 1.
Graphical Abstract
Scheme 1: Representative phenanthridine compounds and our synthetic strategy based on Pd-catalyzed sequential...
Figure 1: Substrate scope of the Pd-catalyzed PA-directed C–H arylation reaction. All reactions were carried ...
Figure 2: Substrate scope of this phenanthridine synthesis. All reactions were carried out in a 10 mL glass v...
Graphical Abstract
Scheme 1: Biogenetic origin of Vinca alkaloids.
Scheme 2: Synthetic strategy for velbanamine based on chemoselective dioxygenation.
Scheme 3: Intramolecular oxyamidation of alkene 11 with phenyliodine(III)-bis(trifluoroacetate) (PIFA) by Tel...
Scheme 4: Copper-catalyzed amination of aryliodide.
Scheme 5: Revised PIFA-promoted cyclization of amide 11.
Scheme 6: PIFA-promoted cyclization to synthesize lactone.
Figure 1: Hydrolysis of iminolactone 18 under basic conditions.
Scheme 7: “Stop-and-flow” strategy for the stepwise dioxygenation of alkenes.
Scheme 8: “Stop-and-flow” strategy for the construction of γ-lactone derivatives.
Graphical Abstract
Figure 1: Representative majucin-type Illicium sesquiterpenes.
Figure 2: Comparison of core skeleton synthetic strategies.
Scheme 1: Organocatalyzed asymmetric Robinson annulation.
Scheme 2: Early stage A-ring functionalization.
Scheme 3: Synthesis of core scaffold 9.
Graphical Abstract
Figure 1: An aza-[3 + 3] annulation.
Scheme 1: Aza-[3 + 3] annulations with enones.
Figure 2: Possible natural-product targets.
Scheme 2: Synthesis of the annulation precursor enone 10.
Scheme 3: Propyleine-isopropeleine interconversion.
Figure 3: Relative stabilities of propyleine and isopropyleine.
Scheme 4: Retrosynthesis of propyleine (12).
Scheme 5: Synthesis of allyl alcohol 25.
Graphical Abstract
Figure 1: Lyconadin A.
Scheme 1: Retrosynthetic analysis of 1.
Scheme 2: Synthesis of triether 15.
Scheme 3: Synthesis and attempted ring-opening of epoxide 17.
Scheme 4: Attempted protection of 14 and silyl migration.
Scheme 5: Synthesis and ring-opening rearrangement of epoxide 25.
Scheme 6: Proposed mechanism for generation of alcohol 26.
Scheme 7: Synthesis of epoxide 29 from alcohol 26 (asterisks indicate relative but not absolute stereochemist...
Graphical Abstract
Figure 1: Examples of naturally occurring quinazoline alkaloids.
Figure 2: Different approaches to the synthesis of quinazoline alkaloid structures.
Scheme 1: Oxidation of other aminal systems.
Graphical Abstract
Scheme 1: Synthetic approach toward N-arylpyrroles.
Scheme 2: Isomerization of pyrrolidine 4a (PMP: 4-methoxyphenyl).
Scheme 3: Preparation of N-arylpyrroles 5a–h (unless otherwise specified, yields in brackets refer to the iso...
Scheme 4: Variation of imines.
Scheme 5: Possible mechanism.
Scheme 6: Bis(heteroaryl)methylene oxidation of 5a–f.
Graphical Abstract
Figure 1: Structures of the ripostatins.
Figure 2: Retrosynthesis of ripostatin A.
Scheme 1: Nickel-catalyzed reductive coupling of alkynes and epoxides.
Figure 3: Proposed retrosynthesis of ripostatin A featuring enyne–epoxide reductive coupling and rearrangemen...
Scheme 2: Potential transition states and stereochemical outcomes for a concerted 1,5-hydrogen rearrangement.
Scheme 3: Rearrangements of vinylcyclopropanes to acylic 1,4-dienes.
Scheme 4: Synthesis of cyclopropyl enyne.
Scheme 5: Synthesis of model epoxide for investigation of the nickel-catalyzed coupling reaction.
Scheme 6: Nickel-catalyzed enyne–epoxide reductive coupling reaction.
Scheme 7: Proposed mechanism for the nickel-catalyzed coupling reaction of alkynes or enynes with epoxides.
Scheme 8: Regioselectivity changes in reductive couplings of alkynes and 3-oxygenated epoxides.
Scheme 9: Enyne reductive coupling with 1,2-epoxyoctane.
Figure 4: Initial retrosynthesis of the epoxide fragment by using dithiane coupling.
Scheme 10: Synthesis of dithiane by Claisen rearrangement.
Scheme 11: Deuterium labeling reveals that the allylic/benzylic site is most acidic.
Scheme 12: Oxy-Michael addition to δ-hydroxy-α,β-enones.
Figure 5: Revised retrosynthesis of epoxide 5.
Scheme 13: Synthesis of functionalized ketone by oxy-Michael addition.
Figure 6: Retrosynthesis by using iodocylization to introduce the epoxide.
Scheme 14: Synthesis of ketone 57 using thiazolidinethione chiral auxiliary.
Figure 7: Retrosynthesis involving decarboxylation of a β-ketoester.
Scheme 15: Synthesis of β-ketoester 61.
Scheme 16: Decarboxylation of 61 under Krapcho conditions.
Scheme 17: Improved synthesis of 63 and attempted iodocyclization.
Figure 8: Retrosynthesis utilizing Rychnovsky’s cyanohydrin acetonide methodology.
Scheme 18: Synthesis of cyanohydrin acetonide and attempted alkylation with epoxide.
Scheme 19: Allylation of acetonide and conversion to aldehyde.
Scheme 20: Synthesis of the epoxide precursor by an aldol−decarboxylation sequence.
Graphical Abstract
Figure 1: Catalysts and seleno reagents evaluated in this study.
Figure 2: Generality for substitution at the indoline moiety. The reaction was performed in 0.1 mmol scale in...
Figure 3: X-ray crystallography of 4a catalyzed by (S)-3b.
Scheme 1: The plausible reaction mechanism.
Scheme 2: Scale up of the protocol and synthetic application.
Graphical Abstract
Scheme 1: Proposed biosynthetic pathway and strategic analysis for synthesis of katsumadain A.
Scheme 2: Preliminary results of the biomimetic synthesis of katsumadain A.
Scheme 3: Total synthesis of both enantiomers of katsumadain A.
Graphical Abstract
Graphical Abstract
Figure 1: Structures of resolvins D1 (1) and D2 (2).
Scheme 1: Retrosynthetic analysis of RvD2 (1).
Scheme 2: Synthesis of aldehyde 7 and phosphonium salt 6.
Scheme 3: Synthesis of vinyl iodide 4.
Scheme 4: Synthesis of enyne 3.
Scheme 5: Completion of the synthesis of RvD2 (1).