Rearrangements of organometallic compounds. XII. Generation of boracarbenoid and boracyclopropene intermediates from the photolysis of tetraorganoborate salts in aprotic media

Eisch, John J.; Tamao, Kohei; Wilcsek, Robert J.

doi:10.1021/ja00837a037

Cited by 36 publications

(9 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The integration products, 7b-12b, besides the major products, iodotoluene and biphenyl. No phenyl radical tions of the tolyl radical addition products did not significantly differ from those of the butyl radical addition products were detected, indicating that only the iodonium cation released the aryl radical addition products (Scheme 2 tion of iodonium cation could be similar to that of other iodonium salts 7,14 resulting in the formation of aryl radical and aryl iodide, while the decomposition of the tetraphenylborate anion could be similar to that of other borate salts 16 resulting in the formation of biphenyl. The formation of biphenyl in both cases is likely via a similar route to that Scheme 3.…”

mentioning

confidence: 98%

“…rangement rather than from combination of phenyl radicals. 16 We monitored the decomposition of ioIodonium borate salts are tight-ion pairs, so electron transfer should occur directly from anion donium borate salts by 1 H-NMR techniques. Solutions of iodonium borate salts (0.0167M) in deuterto cation within a solvent cage when they are irraated acetone in NMR sample tubes were purged by argon for 10 min.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and study of iodonium borate salts as photoinitiators

Feng

Zang

Martin

et al. 1998

J. Polym. Sci. A Polym. Chem.

View full text Add to dashboard Cite

Iodonium butyltriphenylborate salts (AI+Ar′Ph3B−R), (Bu) were found to be more efficient than iodonium tetraphenylborate salts (RPh) when used as photoinitiators for the polymerization of acrylates. Relative photodecomposition rates were also different. It was found from a study of the photoreaction of iodonium borate salts with a model monomer, methyl methacrylate, that iodonium butyltriphenylborate salts simultaneously produce a butyl radical from the borate anion and an aryl radical from the iodonium cation upon irradiation. Both radicals initiate polymerization. Iodonium tetraphenylborate salts were found to release an aryl radical, but only from the iodonium cation. Iodonium borate salts exhibit strong absorption below 300 nm with a tail absorption above 400 nm. Thus, iodonium butyltriphenyl borate salts are efficient photoinitiators even when used with visible light. When a photosensitizer such as 5,7‐diiodo‐3‐butoxy‐6‐fluorone is employed, iodonium butyltriphenylborate salts are rendered much more efficient for visible light photopolymerization. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1667–1677, 1998

show abstract

mentioning

confidence: 98%

mentioning

confidence: 99%

Synthesis and study of iodonium borate salts as photoinitiators

Feng

Zang

Martin

et al. 1998

J. Polym. Sci. A Polym. Chem.

View full text Add to dashboard Cite

show abstract

“…12,13 The authors assumed transient Ph 2 B À Na þ (7), which reacted with diphenylacetylene to form boranuidacyclopropene 8, and then 8 was protonated to give cis-stilbene under the reaction conditions. Two years later, Schuster et al doubted the formation of Ph 2 B À Na þ (7) because they considered another mechanism for the formation of biphenyl in the photolysis of 6 (Scheme 2, bottom).…”

Section: In 1975 Eisch Et Al Reported Photolysis Of Ph 4 Bmentioning

confidence: 99%

Recent Developments of Boryl Anions: Boron Analogues of Carbanion

Yamashita

Nozaki

2008

Bulletin of the Chemical Society of Japan

View full text Add to dashboard Cite

This account reviews the chemistry of “boryl anion.” Boryl anions can be classified with their metallic counterpart, such as Li, Mg, Cu, and Zn in a similar manner to the classification of carbanions. The early attempts to generate boryl anions by reductive dehalogenation of haloboranes with alkali metal or photolysis of tetraphenylborate compounds had no modern spectroscopic identification of the reactive “boryl anion.” Recent developments of base-stabilized boryl anion, base–BH2−M+ (base = NEt3 or PCy3, M=K or Li), and generation of borylcopper species, “pinBCuL,” have opened a new area of organoboron chemistry. Recently, we have synthesized a lithium salt of boryl anion, boryllithium, which reacted with electrophiles as a boron nucleophile. Based on the high reactivity of boryllithium, transmetallation to other metals enables synthesis of a series of borylmetals, such as borylmagnesium, borylcopper, and borylzinc species. All of these compounds were isolated and structurally characterized to have an sp2 boron atom. Reactivity with organic electrophiles could confirm that they behaved as boron nucleophiles.

show abstract

“…In der vorliegenden Arbeit wurde jedoch eine präparativ einfachere Synthese verwendet, die auf der photolytischen Spaltung von Na[BPh 4 ] zu Na[:BPh 2 ] und Biphenyl basiert [24]. Da Na[:BPh 2 ] sehr hydrolyseempfindlich ist, müssen Vorstufe und Lösungsmittel sorgfältig getrocknet werden.…”

Section: Darstellung Von Ph 2 Pc(ph)=c(ph)bph 2 (2)unclassified

“…Dies wird u. a. durch Vergleich des δ P -Wertes mit den Daten anderer Diphenylvinylphosphane bestätigt: ViPPh 2 (δ P = −11,7), cisMeCH=CHPPh 2 (δ P = −32,7), trans-MeCH=CHPPh 2 (δ P = −14,2). Der beobachtete Unterschied wird dem sterischen γ-Effekt zugeschrieben [24]. Mit dem Wert von −15,6 liegt die Phosphorresonanz von 2 für die cis-Anordnung der Substituenten Ph 2 B und Ph 2 P zwar ungewöhnlich niedrig, findet ihre Erklärung allerdings durch die intramolekulare P → B-Wechselwirkung und die damit verbundene Entschirmung des 31 P-Kerns.…”

Section: Darstellung Von Ph 2 Pc(ph)=c(ph)bph 2 (2)unclassified

Alternativ-Liganden, XXXVII. Phosphanliganden mit Bor als Lewis-acidem Zentrum: Synthese und Koordinationseigenschaften / Alternative Ligands, XXXVII. Phosphane Ligands with Boron as Lewis-acidic Centre: Synthesis and Coordinating Properties

Grobe

Lütke-Brochtrup

Krebs

et al. 2006

Zeitschrift Für Naturforschung B

View full text Add to dashboard Cite

The complex [Rh(CO)Cl{Me 2 PC(Me)=C(Me)BMe 2 } 2 ] (5) has been prepared again in order to prove its structure with weak bonding interactions between the basic rhodium centre and the Lewisacidic Me 2 B group of the donor/acceptor ligand Me 2 PC(Me)=C(Me)BMe 2 (1). For further investigations additional ligands with P-donor and B-acceptor centres, e. g. Ph 2 PC(Ph)=C(Ph)BPh 2 (2), B(OCH 2 PMe 2 ) 3 (3), and B(CH 2 CH 2 PMe 2 ) 3 (4), have been prepared and the coordinating properties have been studied by reactions of 1 and 4 with [(π-C 5 Me 5 )Rh(CO) 2 ] and Pd(PPh 3 ) 4 , respectively. Because single crystals of the products [(π-C 5 Me 5 )Rh(CO)Me 2 PC(Me)=C(Me)BMe 2 ] (6), [(π-C 5 Me 5 )Rh(CO){Me 2 PC(Me)=C(Me)BMe 2 } 2 ] (7) as well as [Pd{B(CH 2 CH 2 PMe 2 ) 3 }] (8) or [(Ph 3 P)Pd{B(CH 2 CH 2 PMe 2 ) 3 }] (9) could not be generated, quantum chemical calculations have been used to elucidate the coordination geometry expected for 5, 8 and 9. The calculations support the structure of 5 within the expected limitations of the experimental and theoretical methods andin spite of the extremely soft coordination sphere of 8 and 9 -are in accord with spectroscopic results for the cage structures.

show abstract

Rearrangements of organometallic compounds. XII. Generation of boracarbenoid and boracyclopropene intermediates from the photolysis of tetraorganoborate salts in aprotic media

Cited by 36 publications

References 4 publications

Synthesis and study of iodonium borate salts as photoinitiators

Synthesis and study of iodonium borate salts as photoinitiators

Recent Developments of Boryl Anions: Boron Analogues of Carbanion

Alternativ-Liganden, XXXVII. Phosphanliganden mit Bor als Lewis-acidem Zentrum: Synthese und Koordinationseigenschaften / Alternative Ligands, XXXVII. Phosphane Ligands with Boron as Lewis-acidic Centre: Synthesis and Coordinating Properties

Contact Info

Product

Resources

About