Michael E. Blake

Complexation of stable carbenes with alkali metals

Stable diaminocarbenes, including imidazol-2-ylidenes, undergo complexation with lithium, sodium and potassium species; the crystal structure of a complex of 1,3-diisopropyl-3,4,5,6-tetrahydropyrimid-2-ylidene 1 with KN(SiMe3)2 is reported.

Bis(N-piperidyl)carbene and its slow dimerisation to tetrakis(N-piperidyl)ethene

An unhindered bis(sec-amino)carbene can be generated by deprotonation of an amidinium ion with lithium diisopropylamide, and undergoes remarkably slow dimerisation to the corresponding tetraaminoethene.

The Suzuki coupling of aryl chlorides in TBAB-water mixtures

Palladium acetate in a mixture of TBAB and water can be used as an effective catalyst for the Suzuki coupling of deactivated aryl chloride substrates.

Preparation of tetraalkylformamidinium salts and related species as precursors to stable carbenes

Methods are described for the preparation of a range of N,N,N′,N′-tetraalkylformamidinium and N,N-dialkyliminium ions 4–20 as anhydrous salts for use as precursors to diamino- and amino-carbenes. These methods include a novel method involving nucleophilic addition to formamides followed by trapping with electrophiles such as triflic anhydride, various methods of formamide activation, exchange reactions involving orthoesters and the transamination of amidinium salts, and alkylation methods.

The first example of a doubly orthometallated aryl bis(phosphinite) ligand

The reaction of 2-methylresorcinolbis(diphenyl)phosphinite with Pd(TFA)2 gives a dimeric tetranuclear complex which contains two of the ligands, each di-orthopalladated; the X-ray structure of the complex has been determined and its reactivity briefly examined.