Synthesis of the 3-aza-[7]-paracyclophane core of haouamine A and B

The synthesis of the highly strained 3-aza-[7]-paracyclophane core of haouamines A and B is based on a macrocyclization-aromatization protocol, allowing for a stepwise increase in ring strain and establishing the oxygenation pattern of the natural products. © 2006 American Chemical Society

Concise synthesis of all four stereoisomers of 3-(tert-butoxycarbonyl)-3-azabicyclo[3.1.0]hexane-2-carboxylic acid

A concise synthesis of all four stereoisomers of 3-(tert-butoxycarbonyl)-3-azabicyclo[3.1.0]hexane-2-carboxylic acid has been developed; thereby significantly shortening the known literature procedures for the syntheses of these unnatural amino acids. With a simple adjustment of the reaction conditions, we were able to obtain either pure cis or trans acid. Optical resolution was accomplished via diastereomeric salt formation or alternatively via chromatography on a chiral stationary phase. Finally, ab-initio calculations gave an explanation for the observed cis selectivity in the initial step

New advances in dual stereocontrol for asymmetric reactions

[EN] Achieving dual stereocontrol in asymmetric reactions using a single enantiomer for the building of the chiral catalyst or auxiliary is a very important goal in enantioselective synthesis as it eliminates the need for having available the two enantiomers of the auxiliary or catalyst designed. Recent strategies and advances towards this goal during the last four years will be discussed throughout this review.Financial support for our work has been provided by MINECO (CTQ2011-28903-C02-01) and GV (PROMETEO/2012/020).Escorihuela Fuentes, J.; Burguete Azcarate, MI.; Luis Lafuente, S. (2013). New advances in dual stereocontrol for asymmetric reactions. Chemical Society Reviews. 42(14):5595-5617. https://doi.org/10.1039/c3cs60068hS55955617421