10. Patented Literature 2616 10.1. Esterification 2616 10.2. Ether Formation 2619 10.2.1. Etherification without Cyclization 2619 10.2.2. Etherification with Cyclization 2624 10.3. N-Alkylation 2625 10.4. Other Reactions 2627 11. Summary and Outlook 2628 12. Note Added in Proof 2628 13. Abbreviations Used in This Review 2629 14. Acknowledgments 2629 15. Supporting Information Available 2630 16. References 2630

Mitsunobu and Related Reactions: Advances and Applications

Chemistry and Biology of Mycotoxins and Related Fungal Metabolites

Rephrasing Fuson's original formulation, the principle of
vinylogy explains how the influence of a functional group may be relayed to a distant point in the molecule when these two sites are connected to by conjugated unsaturated linkages, such as double and triple bonds or aromatic moieties.
This principle has been applied, over the years, to the majority of polar carbon-carbon bond-forming reactions of various repute, including the venerable Michael addition reaction, where the electrophilic -CdX site (1,2-addition) is “usurped” by a remote conjugated -RCdCR-CdX position (1,4-addition). The aldol addition reaction and the related
Mannich process, both fundamental pillars of organic synthesis, have not escaped this fate, and both of their
vinylogous extensions have emerged as extremely valuable
synthetic methodologies.

The Vinylogous Aldol and Related Addition Reactions: Ten Years of Progress†

Multicomponent reactions have gained significant importance as a tool for the synthesis of a wide variety of useful compounds, including pharmaceuticals. In this context, the multiple component approach is especially appealing in view of the fact that products are formed in a single step, and the diversity can be readily achieved simply by varying the reacting components. The eco-friendly, solvent-free multicomponent approach opens up numerous possibilities for conducting rapid organic synthesis and functional group transformations more efficiently. Additionally, there are distinct advantages of these solvent-free protocols since they provide reduction or elimination of solvents thereby preventing pollution in organic synthesis “at source”. The chemo-, regio- or stereoselective synthesis of high-value chemical entities and parallel synthesis to generate a library of small molecules will add to the growth of multicomponent solvent-free reactions in the near future. In this review we summarized the results reported mainly within the last 10 years. It is quite clear from the growing number of emerging publications in this field that the possibility to utilize multicomponent technology allows reaction conditions to be accessed that are very valuable for organic synthesis. Therefore, diversity oriented synthesis (DOS) is rapidly becoming one of the paradigms in the process of modern drug discovery. This has spurred research in those fields of chemical investigation that lead to the rapid assembly of not only molecular diversity, but also molecular complexity. As a consequence multi-component as well as domino or related reactions are witnessing a new spring.

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Recent developments in solvent-free multicomponent reactions: a perfect synergy for eco-compatible organic synthesis

Recent Advances in the Total Synthesis of Piperidine and Pyrrolidine Natural Alkaloids with Ring‐Closing Metathesis as a Key Step

An enantioselective synthesis of the piperidine alkaloids (+)-sedamine and (-)-prosophylline is reported. The synthesis of (+)-sedamine has been achieved in 12 steps with an overall yield of 20% from benzaldehyde, and (-)-prosophylline was obtained in 15 steps with an overall yield of 9.2%, starting from D-glyceraldehyde acetonide 14. The key steps are enantioselective allyltitanation reactions and ring-closing or cross-metathesis reactions.

Enantioselective allyltitanations and metathesis reactions. Application to the synthesis of piperidine alkaloids (+)-sedamine and (-)-prosophylline.

An enantioselective synthesis of the indolizidine alkaloid (-)-slaframine from aldehyde 1 is reported. The stereogenic centers at C-1 and C-8a are introduced by an enantioselective allyltitanation and a Mitsunobu reaction. Reductive double cyclization of the acyclic compound (-)-10 affords the bicyclic skeleton of (-)-slaframine.

Enantioselective Allyltitanation. Synthesis of (-)-Slaframine

Synthesis of vulpinic and pulvinic acids from tetronic acid

Enantiopure allyltitanium and crotyltitanium complexes allow the enantioselective synthesis of 1,2-, 1,3- and 1,5-diols as well as polypropionate units. These complexes can be used in the synthesis of a great number of biologically active compounds.

Chiral titanium complexes. Synthesis of optically active unsaturated alcohols, diols, polypropionates and their use in the synthesis of biologically active compounds

A short, convergent synthesis of the mushroom pigment norbadione A is described. The construction of an appropriately substituted naphtholactone intermediate involved a regioselective Diels-Alder reaction between a bis(triisopropylsilyloxy)diene and 2,6-dichlorobenzo-1,4-quinone. A double Suzuki-Miyaura cross-coupling between a diboronate and two identical enol triflates was another key feature of the synthesis.

Catherine Willis

Papers

Enantioselective allyltitanations and metathesis reactions. Application to the synthesis of piperidine alkaloids (+)-sedamine and (-)-prosophylline.

Enantioselective Allyltitanation. Synthesis of (-)-Slaframine

Synthesis of vulpinic and pulvinic acids from tetronic acid

Chiral titanium complexes. Synthesis of optically active unsaturated alcohols, diols, polypropionates and their use in the synthesis of biologically active compounds

Total Synthesis of Norbadione A