Scope of the reaction of organoboranes with organolithiums as a method of preparation of lithium organoborates. Stability of lithium organoborates

Negishi, E.; IDACAVAGE, M. J.; Chiu, K. K.; Yoshida, Takao; Abramovitch, Akiva; Goettel, Mary E.; Silveira, Augustine; Bretherick, Henry D.

doi:10.1039/p29780001225

Cited by 17 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Materials. Trimethylborane, LiBMe 4 , LiBMePh 3 , and various pyridinium salts in Chart were prepared according to the literature procedures. Methyllithium, tri( n -butyl)borane, triphenylborane, and sodium tetraphenylborate were from Aldrich and used as received.…”

Section: Methodsmentioning

confidence: 99%

Alkylation of Pyridinium Acceptors via Thermal and Photoinduced Electron Transfer in Charge-Transfer Salts with Organoborates

Zhu

Kochi

1998

Organometallics

View full text Add to dashboard Cite

Colored salts of pyridinium tetraalkylborates [Py +,BR4 -] are readily isolated by the metathesis of LiBMe4, LiBMePh3, or NaBPh4 with a series of pyridinium triflates in aqueous solution. The interionic charge-transfer (CT) interaction between the organoborate anions and the pyridinium cations is established by their characteristic charge-transfer absorption bands and X-ray crystal structures. Thermal and photochemical CT activations of the salts lead to efficient methyl transfer from tetramethylborate (or methyltriphenylborate) to the pyridinium cations to afford the various nucleophilic adducts (Py-Me) in good yields. Contact charge-transfer ion pairs are identified as the critical intermediates in the formal nucleophilic addition and thus play important roles in determining the regiochemistry of the alkylation and the solid-state reactivity of the [Py +,BR4 -] salts.

show abstract

Section: Methodsmentioning

confidence: 99%

Alkylation of Pyridinium Acceptors via Thermal and Photoinduced Electron Transfer in Charge-Transfer Salts with Organoborates

Zhu

Kochi

1998

Organometallics

View full text Add to dashboard Cite

show abstract

“…However, Frohn and co-workers had shown that alkynyldifluoroboranes can be isolated and characterized as single compounds upon the treatment of alkynyltrifuoroborates with boron trifluoride . Nevertheless, alkyne exchange between organoboranes and -borates has been reported by Negishi et al First, the ligand exchange reaction between two (phenylethynyl)borane ( IM ) monomers was considered. Following ref , the enthalpy profile for the ligand exchange reaction between two IM monomers is shown in Scheme .…”

Section: Theoretical Resultsmentioning

confidence: 99%

A Mechanistic Study of the Lewis Base-Directed Cycloaddition of 2-Pyrones and Alkynylboranes

et al. 2014

View full text Add to dashboard Cite

Significant rate enhancements in the Diels-Alder reaction of alkynes and 2-pyrones bearing a Lewis basic group are observed when a combination of alkynyltrifluoroborates and BF 3 .OEt 2 are used. This process generates functionalized aromatic compounds with complete regiocontrol. The origin of the observed rate enhancement has been studied by DFT methods, and they appear to originate for coordination of the diene substrate to a mixture of alkynylborane intermediates, followed by a Lewis acid mediated product equilibration step. Evidence for this mechanism is presented, as is the enhanced promotion of the cycloaddition via the use of alternative Lewis acid promoters.2

show abstract

By Addition to Polar Organometallics to Form Organoborates

Brown¹,

Zaidlewicz²

1989

Inorganic Reactions and Methods

View full text Add to dashboard Cite

Scope of the reaction of organoboranes with organolithiums as a method of preparation of lithium organoborates. Stability of lithium organoborates

Cited by 17 publications

References 0 publications

Alkylation of Pyridinium Acceptors via Thermal and Photoinduced Electron Transfer in Charge-Transfer Salts with Organoborates

Alkylation of Pyridinium Acceptors via Thermal and Photoinduced Electron Transfer in Charge-Transfer Salts with Organoborates

A Mechanistic Study of the Lewis Base-Directed Cycloaddition of 2-Pyrones and Alkynylboranes

By Addition to Polar Organometallics to Form Organoborates

Contact Info

Product

Resources

About