David Andrew Neel

Asymmetric synthesis of 4-[(t-butoxycarbonyl)amino]-pyrazolidin-3-one : precursor to bicyclic pyrazolidinone antibacterials

Abstract The preparation of chiral pyrazolidin-3-one 1 is described. The key step was cyclization via a Mitsunobu reaction using the trifluoroacetyl group to activate the terminal nitrogen.

Synthesis of bisindolylmaleimides using a palladium catalyzed cross-coupling reaction

Bisindolylmaleimides are known to be potent and selective PKC inhibitors. A new synthesis of this class of compound is reported. The key step is a Suzuki cross-coupling reaction using a readily available indolylmaleimide triflate intermediate.

Synthesis of bisindolylmaleimide macrocycles

Abstract The synthesis of a novel class of N-N′-macrocyclic bisindolylmaleimides is reported. The key step involves a remarkably efficient intramolecular cyclization reaction. The method was further developed to provide an efficient synthesis of this type of macrocycle through an intermolecular alkylation with subsequent intramolecular cyclization.

Synthesis of a 3-keto bicyclic pyrazolidinone using a Curtius rearrangement

The synthesis of bicyclic pyrazolidinone 2 is described. Traditional methods for penem and cephem ring cyclization were found to be unsuccessful and new methodology using a Curtius rearrangement was utilized. The 3-enamine 11 was hydrolysed to the desired β-keto ester 2b without substantial loss of the t-BOC protecting group.