Enantioselective Synthesis of 4‐Hydroxy‐2‐cyclohexenones through a Multicomponent Cyclization

Barluenga, José; Suero, Marcos G.; Campa, Raquel de la; Flórez, Josefa

doi:10.1002/ange.201004413

Cited by 4 publications

(2 citation statements)

References 45 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More specific transformations include the asymmetric propargylboration of aldehydes using 10-trimethylsilyl-9-borabicyclo[3.3.2]decanes, 130 or Barluenga’s multicomponent reaction of chromium carbenes 73 , oxazolidine-2-ones lithium enolates 74 , and Grignard reagents 75 to yield highly substituted cyclohexenones 76 bearing allenolic units. 131 Central-to-central chirality transfer is reported, using optically pure oxazolidines as chiral inductors, and yielding allenols 76 showing up to 99% ee ( Scheme 16 ).…”

Section: Synthesis Of Allenolsmentioning

confidence: 99%

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

2021

View full text Add to dashboard Cite

The allene functionality has participated in one of the most exciting voyages in organic chemistry, from chemical curiosities to a recurring building block in modern organic chemistry. In the last decades, a special kind of allene, namely, allenol, has emerged. Allenols, formed by an allene moiety and a hydroxyl functional group with diverse connectivity, have become common building blocks for the synthesis of a wide range of structures and frequent motif in naturally occurring systems. The synergistic effect of the allene and hydroxyl functional groups enables allenols to be considered as a unique and sole functionality exhibiting a special reactivity. This Review summarizes the most significant contributions to the chemistry of allenols that appeared during the past decade, with emphasis on their synthesis, reactivity, and occurrence in natural products.

show abstract

Section: Synthesis Of Allenolsmentioning

confidence: 99%

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

2021

View full text Add to dashboard Cite

show abstract

“… 1 A striking example is given by monochromium complexes with a Fischer alkylidene ligand of general formula [Cr(CO) 5 {=C(OR)R′}], which have emerged as versatile stoichiometric reagents for multicomponent cyclization reactions, providing access to highly functionalized organic molecules incorporating the alkylidene moiety. 1a , 1b , 2 This approach has been largely exploited for the preparation of a variety of fine chemicals (e.g., pharmaceuticals and natural products). 2a , 3 The unique combination of the favorable properties of iron (i.e., its abundance, low cost, and nontoxicity) renders easily available iron compounds ideal candidates for the development of metal-directed processes.…”

Section: Introductionmentioning

confidence: 99%

Tetrasubstituted Selenophenes from the Stepwise Assembly of Molecular Fragments on a Diiron Frame and Final Cleavage of a Bridging Alkylidene

et al. 2020

View full text Add to dashboard Cite

A series of 2,3-dicarboxylato-5-acetyl-4-aminoselenophenes, 5a – j , was obtained via the uncommon assembly of building blocks on a diiron platform, starting from commercial [Fe 2 Cp 2 (CO) 4 ] through the stepwise formation of diiron complexes [ 2a – d ]CF 3 SO 3 , 3a – d , and 4a – j . The selenophene-substituted bridging alkylidene ligand in 4a – j is removed from coordination upon treatment with water in air under mild conditions (ambient temperature in most cases), affording 5a – j in good to excellent yields. This process is highly selective and is accompanied by the disruption of the organometallic scaffold: cyclopentadiene (CpH) and lepidocrocite (γ-FeO(OH)) were identified by NMR and Raman analyses at the end of one representative reaction. The straightforward cleavage of the linkage between a bridging Fischer alkylidene and two (or more) metal centers, as observed here, is an unprecedented reaction in organometallic chemistry: in the present case, the carbene function is converted to a ketone which is incorporated into the organic product. DFT calculations and electrochemical experiments were carried out to give insight into the release of the selenophene-alkylidene ligand. Compounds 5a – j were fully characterized by elemental analysis, mass spectrometry, IR, and multinuclear NMR spectroscopy and by X-ray diffraction and cyclic voltammetry in one case.

show abstract

Enantioselective Multicomponent Synthesis of Fused 6–5 Bicyclic 2‐Butenolides by a Cascade Heterobicyclisation Process

Suero¹,

Campa²,

Torre-Fernández³

et al. 2012

Chemistry A European J

View full text Add to dashboard Cite

The successive coupling of an alkoxy(aryl/heteroaryl)carbene complex of chromium with either a ketone or an imide lithium enolate and then a 3-substituted (H, TMS, PhCH(2), PhCH(2)CH(2), Me) propargylic organomagnesium reagent has afforded novel hydroxy-substituted bicyclic [4.3.0]-γ-alkylidene-2-butenolides with three modular points that has allowed the efficient introduction of molecular complexity, including a homopropargylic alcohol core. The selective formation of these five- or six-component heterobicyclisation products is the result of the regioselective integration of the Grignard reagent as a propargyl fragment followed by a cascade CO/alkyne/CO insertion, ketene trapping and elimination sequence. By using lithium enolates of chiral N-acetyl-2-oxazolidinones and the corresponding propargylic organocerium reagents, both enantiomers of these bicyclic heterocycles were efficiently prepared with very high enantiomeric purity. Architecturally, these fused bicyclic butenolides are characterised by a highly unsaturated and oxygenated core and they exhibit strong blue fluorescence in solution.

show abstract

Enantioselective Synthesis of 4‐Hydroxy‐2‐cyclohexenones through a Multicomponent Cyclization

Cited by 4 publications

References 45 publications

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

Tetrasubstituted Selenophenes from the Stepwise Assembly of Molecular Fragments on a Diiron Frame and Final Cleavage of a Bridging Alkylidene

Enantioselective Multicomponent Synthesis of Fused 6–5 Bicyclic 2‐Butenolides by a Cascade Heterobicyclisation Process

Contact Info

Product

Resources

About