Search

Herein, we describe how computational mechanistic understanding has led directly to the discovery of new 2H‐phosphindole for C−CAr bond activation and dearomatization reaction. We uncover an unexpected intramolecular C−H bond activation with a 2H‐phosphindole derivative. This new intriguing experimental observation and further theoretical studies led to an extension of the reaction mechanism with 2H‐phosphindole. Through DFT calculations, we confirm that within a five‐membered ring, the polarizable PC3 unit orchestrates the formation of an electrophilic phosphorus atom (P+) and a nucleophilic carbon atom (C−). This kinetically accessible ambiphilic phosphorus/carbon couple is spatially separated by geometric constraints, and their reactivity is modulated through structural resonance. [ABSTRACT FROM AUTHOR]

Abstract: The wide occurrence of carbon–phosphorus bond activation in modern organic synthesis, catalyst deactivation, and biological process has attracted interest for synthetic applications. Over the past few decades, transition‐metal‐mediated transformations have become extremely powerful tools in organic synthesis. In this review, considerable progress that has been made in catalytic activations and transformations of carbon–phosphorus bonds within the coordination sphere of transition metals is described. Mechanistic information is also presented, and it is hoped that this review not only provides an account of the state of the art in the field, but also highlights the future potential of these reactions in organic synthesis. [ABSTRACT FROM AUTHOR]

The first pyrroloazaphosphinines with nitrogen at the junction, 7a and 7b, have been prepared by a special route involving the collapse of the phosphorus bridges of appropriate 7-phosphanorbornenes. The parent molecule 7a has a strictly planar azaphosphinine ring with some electronic delocalization according to DFT computations. Its P=C double bond does not react with 2,3-dimethylbutadiene unless P is coordinated toMo(CO)5. Compound 7a reacts with CuI to give a new type of polymeric complex [–Cu-μ2-7a–]n in which P acts as a bridging ligand and the ligand planes are antiparallel. The benzo-annulated and bromo-substituted 7b displays a skewed ring according to DFT computations and its P=C double bond is reactive toward 2,3-dimethylbutadiene without complexation. [ABSTRACT FROM AUTHOR]

The stabilization of a phosphirane ring by complexation to tungsten pentacarbonyl allows the emergence of the Cloke-Wilson rearrangement in 1-acylphosphirane complexes around 130 °C. Contrary to the cyclopropane case, this transformation of the 1-acylphosphirane to the 1,3-oxaphosphol-3-ene complexes is reversible. It is favored by a 2-phenyl, and even a 2-vinyl substitution. The 1,3-oxaphosphol-3-ene complexes are trapped by conjugated dienes. [ABSTRACT FROM AUTHOR]

Treatment of ortho-(diphenylphosphanyl)phenyl nitriles with an excess of lithium at room temperature in THF gives 1,2-azaphosphindolides, which can react with RX (benzyl bromide, 1-bromopropane, and 1,2-dibromoethane) to form 2H-1,2-azaphosphindoles and give the aromatic 1H-1,2-azaphosphindoles upon protonation. [ABSTRACT FROM AUTHOR]

ortho-Phosphinobenzonitriles (or thieno, pyridino analogues) react with dimethyl acetylenedicarboxylate between -78 °C and room temperature to give annelated λ5-phosphanaphthalenes. Interesting variations of the fluorescence properties are observed when the R substituents at P are alkyl or aryl. When R = tBu, the thermolysis of the product affords the corresponding trivalent phosphanaphthalene. [ABSTRACT FROM AUTHOR]

Blue light-emitting phosphorus and silicon-bridged stilbenes have been synthesized and characterized. The organic light-emitting diodes (OLEDs) fabricated with these compounds demonstrate that this new type of phospholes is a promising material for deep blue fluorescence emitters. [ABSTRACT FROM AUTHOR]

The available data on the activation of A–H sigma bonds by electrophilic terminal phosphinidene complexes are reviewed. Theoretical computations allow us to rationalize the experimental results. It appears that a successful insertion needs an initial interaction between the phosphinidene and the A–H bond, such as a donor–acceptor complex with a lone pair, a Coulombic interaction due to a negative charge on A or H, or a proximity effect. [ABSTRACT FROM AUTHOR]

Abstract P=CH 2 ylides derived from ortho -alkynylphenylphosphines readily cyclize to give phosphindole derivatives. With a stabilized ylide such as P=CHC(O)Ph, the outcome of the reaction is completely different. The reaction proceeds at high temperature and produces phosphanaphthalenes. Graphical abstract Image 1 Highlights • To the best of our knowledge, this paper describes the first instance where the intramolecular cyclization of an ylide onto a non-activated alkene completely shifts from the formation of a 5-membered to a 6-membered ring according to the nucleophilicity of the ylide. [ABSTRACT FROM AUTHOR]

The first general synthesis of phospholides and annelated phospholides starting from open-chain precursors is presented. [ABSTRACT FROM AUTHOR]