160207-37-4Relevant academic research and scientific papers
A metathetical cycloaddition-cycloreversion approach to the formation of furan scaffold libraries
Whitehouse, Darren L.,Nelson Jr., Kingsley H.,Savinov, Sergey N.,Loewe, Ralf S.,Austin, David J.
, p. 1273 - 1282 (2007/10/03)
A general cycloaddition-cycloreversion metathesis procedure for the selective formation of a furan-based template-directed scaffold is described. In addition, features relative to library construction, such as the chemoselective nature of dipole formation, are discussed. Through the investigation of the temperature sensitive cleavage step, the furan synthesis was found to be accelerated by aqueous medium at physiological temperature leading to pure product from the solid-phase under biologically relevant conditions. The chemoselective nature of the rhodium(II) mediated cycloaddition allowed the selective formation of a key dipole intermediate, in the presence of a number of carbene-active functional groups, to facilitate the split-pool combinatorial synthesis of a small library of compounds. Copyright (C) 1998 Elsevier Science Ltd.
Ligand effects in the rhodium(II) catalysed reactions of diazoamides and diazoimides
Miah, Soyfur,Slawin, Alexandra M. Z.,Moody, Christopher J.,Sheehan, Scott M.,Marino Jr., Joseph P.,Semones, Mark A.,Padwa, Albert,Richards, Ian C.
, p. 2489 - 2514 (2007/10/03)
A range of substituted α-diazoamides 1-8 and diazoimides 9-12 was prepared from the corresponding amines or amides. Rhodium(II) catalysed decomposition of the diazoamides resulted in attack on the aromatic ring to give oxindoles or attack on the alkyl group to give either β-lactams or cycloheptapyrrolones. The chemoselectivity of the rhodium carbenoid intermediate was dependent on the metal ligands, fluorinated carboxamides strongly promoting attack on aromatic rings in preference to other processes. Decomposition of the diazoimides resulted in intramolecular attack on the carbonyl group to give an ylide which could be trapped inter- or intramolecularly. X-Ray crystal structures are reported for the diazo compounds 2 and 4, the indoles 17 and 25, the β-lactam 20, the cycloheptapyrrolones 24 and 28, the dimer 29 and the Pictet Spengler product 39.
