trans versus geminal Electron Delocalization in Tetra- and Diethynylethenes: A New Method of Analysis

Bruschi, Maurizio; Giuffreda, Maria; Lüthi, Hans Peter

doi:10.1002/1521-3765(20020916)8:18<4216::aid-chem4216>3.0.co;2-8

Cited by 44 publications

(42 citation statements)

References 24 publications

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“…[23,24] In this analysis, canonical molecular orbitals are first transformed into a set of localized NBOs comprising core orbitals, lone pairs, Rydberg orbitals, and two center orbitals. [25] The subsequent deletion of weakly occupied NBOs leads to energy changes which can be regarded to represent the loss in delocalization energy.…”

Section: Nbo Deletion Studiesmentioning

confidence: 99%

On the Structure of Cross‐Conjugated 2,3‐Diphenylbutadiene

Walree¹,

Wiel²,

Jenneskens³

et al. 2007

Eur J Org Chem

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The structure of the cross-conjugated compound 2,3-diphenylbutadiene was investigated by single-crystal X-ray diffraction and computational methods. In the crystal structure the central butadiene fragment adopts an s-gauche geometry [-55.6(2)°torsion angle φ around the essential single bond], whereas the styrene moieties are close to planarity. MP2/6-311G* calculations show that the s-gauche conformation represents the global minimum along the φ coordinate, but also revealed the existence of an s-trans local minimum.

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Section: Nbo Deletion Studiesmentioning

confidence: 99%

On the Structure of Cross‐Conjugated 2,3‐Diphenylbutadiene

Walree¹,

Wiel²,

Jenneskens³

et al. 2007

Eur J Org Chem

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“…further explore the influence of different conjugation topologies, particularly trans and cis linear conjugations, 33 on the physicochemical properties of the corresponding APA systems. This quest required the preparation of P,C-diacetylenic (E)-3, (Z)-3, and peracetylenic phosphaalkenes 5 (Figure 3).…”

Section: Account Syn Lettmentioning

confidence: 99%

The Fascinating World of Phosphanylphosphonates: From Acetylenic Phosphaalkenes to Reductive Aldehyde Couplings

Mai¹,

Ott²

2019

Synlett

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This account highlights the versatility of phosphanylphosphonates, which can be used for the preparation of phosphorus-containing π-systems and as reagents for the reductive coupling of carbonyl compounds to alkenes. Phosphanylphosphonates with metal fragments coordinated to the P-lone pair have been known for a long time and they have been used for the synthesis of phosphaalkenes by means of the phospha-Horner–Wadsworth–Emmons reaction. With the original aim of incorporating phosphorus heteroatoms into classical all-carbon ethynylethene scaffolds, we entered the field of phosphanylphosphonates with the discovery that these compounds engage in complex cascade reactions with acetylenic ketones, forming 1,2-oxaphospholes, cumulenes, and bisphospholes. Later, we synthesized the first metal-free phosphanylphosphonate, which reacts with aldehydes to yield phosphaalkenes, but gives phospholones when diacetylenic ketones are used as substrates. In the final part of the account, we outline our discovery and the development of an unprecedented carbonyl–carbonyl cross-coupling reaction. This protocol offers a straightforward method for the synthesis of nonsymmetric 1,2-disubstituted alkenes directly from two dissimilar aldehydes.1 Combining Acetylenes with Phosphaalkenes2 Synthetic Examples of Acetylenic Phosphaalkenes3 The Phospha-Horner–Wadsworth–Emmons Approach to Phosphaalkenes3.1 Metal-Coordinated Phosphanylphosphonates3.2 Mechanism of the Phospha-Horner–Wadsworth–Emmons Reaction3.3 The First Metal-Free Phosphanylphosphonate and Its Reactivity with Aldehydes4 Reactions with Acetylenic Ketones4.1 Metal-Coordinated Phosphanylphosphonate and Monoacetylenic Ketones4.2 Metal-Coordinated Phosphanylphosphonate and Diacetylenic Ketones4.3 Metal-Free Phosphanylphosphonate and Diacetylenic Ketones5 Metal-Free Phosphanylphosphonate as a Coupling Reagent for Aldehydes6 E-Alkenes by the Reductive Coupling of Two Aldehydes7 Conclusions and Outlook

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“…The NIR bands nearer 10,000 -15,000 cm - complexes cited above and elsewhere. [66][67][68] The optimized molecular structure of the energetically most stable conformer found in each case and atom labels are shown in Figure 10, and important bond lengths and angles are summarized in Table 3. represents the centroid of the respective Cp* rings here or Cp in the case of the ferrocenyl moiety described below) determined as τ = 67° and 46° for 1 and 2, respectively.…”

Section: Ir Spectroelectrochemicalmentioning

confidence: 99%

Redox Properties of Ferrocenyl Ene-diynyl-Bridged Cp*(dppe)M–C≡C–1,4-(C₆H₄) Complexes

et al. 2018

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trans versus geminal Electron Delocalization in Tetra- and Diethynylethenes: A New Method of Analysis

Cited by 44 publications

References 24 publications

On the Structure of Cross‐Conjugated 2,3‐Diphenylbutadiene

On the Structure of Cross‐Conjugated 2,3‐Diphenylbutadiene

The Fascinating World of Phosphanylphosphonates: From Acetylenic Phosphaalkenes to Reductive Aldehyde Couplings

Redox Properties of Ferrocenyl Ene-diynyl-Bridged Cp*(dppe)M–C≡C–1,4-(C₆H₄) Complexes

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trans versus geminal Electron Delocalization in Tetra- and Diethynylethenes: A New Method of Analysis

Cited by 44 publications

References 24 publications

On the Structure of Cross‐Conjugated 2,3‐Diphenylbutadiene

On the Structure of Cross‐Conjugated 2,3‐Diphenylbutadiene

The Fascinating World of Phosphanylphosphonates: From Acetylenic Phosphaalkenes to Reductive Aldehyde Couplings

Redox Properties of Ferrocenyl Ene-diynyl-Bridged Cp*(dppe)M–C≡C–1,4-(C6H4) Complexes

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Redox Properties of Ferrocenyl Ene-diynyl-Bridged Cp*(dppe)M–C≡C–1,4-(C₆H₄) Complexes