53016-47-0Relevant articles and documents
Organocatalytic, diastereo- and enantioselective synthesis of nonsymmetric cis -stilbene diamines: A platform for the preparation of single-enantiomer cis -imidazolines for protein-protein inhibition
Vara, Brandon A.,Mayasundari, Anand,Tellis, John C.,Danneman, Michael W.,Arredondo, Vanessa,Davis, Tyler A.,Min, Jaeki,Finch, Kristin,Guy, R. Kiplin,Johnston, Jeffrey N.
, p. 6913 - 6938 (2014)
The finding by scientists at Hoffmann-La Roche that cis-imidazolines could disrupt the protein-protein interaction between p53 and MDM2, thereby inducing apoptosis in cancer cells, raised considerable interest in this scaffold over the past decade. Initial routes to these small molecules (i.e., Nutlin-3) provided only the racemic form, with enantiomers being enriched by chromatographic separation using high-pressure liquid chromatography (HPLC) and a chiral stationary phase. Reported here is the first application of an enantioselective aza-Henry approach to nonsymmetric cis-stilbene diamines and cis-imidazolines. Two novel mono(amidine) organocatalysts (MAM) were discovered to provide high levels of enantioselection (>95% ee) across a broad range of substrate combinations. Furthermore, the versatility of the aza-Henry strategy for preparing nonsymmetric cis-imidazolines is illustrated by a comparison of the roles of aryl nitromethane and aryl aldimine in the key step, which revealed unique substrate electronic effects providing direction for aza-Henry substrate-catalyst matching. This method was used to prepare highly substituted cis-4,5-diaryl imidazolines that project unique aromatic rings, and these were evaluated for MDM2-p53 inhibition in a fluorescence polarization assay. The diversification of access to cis-stilbene diamine-derived imidazolines provided by this platform should streamline their further development as chemical tools for disrupting protein-protein interactions.
Continuous Platform to Generate Nitroalkanes On-Demand (in Situ) Using Peracetic Acid-Mediated Oxidation in a PFA Pipes-in-Series Reactor
Tsukanov, Sergey V.,Johnson, Martin D.,May, Scott A.,Kolis, Stanley P.,Yates, Matthew H.,Johnston, Jeffrey N.
, p. 971 - 977 (2018/08/28)
The synthetic utility of the aza-Henry reaction can be diminished on scale by potential hazards associated with the use of peracid to prepare nitroalkane substrates and the nitroalkanes themselves. In response, a continuous and scalable chemistry platform to prepare aliphatic nitroalkanes on-demand using the oxidation of oximes with peracetic acid and direct reaction of the nitroalkane intermediate in an aza-Henry reaction is reported. A uniquely designed pipes-in-series plug-flow tube reactor addresses a range of process challenges, including stability and safe handling of peroxides and nitroalkanes. The subsequent continuous extraction generates a solution of purified nitroalkane, which can be directly used in the following enantioselective aza-Henry chemistry to furnish valuable chiral diamine precursors with high selectivity, thus completely avoiding isolation of the potentially unsafe low-molecular-weight nitroalkane intermediate. A continuous campaign (16 h) established that these conditions were effective in processing 100 g of the oxime and furnishing 1.4 L of nitroalkane solution.
Palladium-catalyzed nitromethylation of aryl halides: An orthogonal formylation equivalent
Walvoord, Ryan R.,Berritt, Simon,Kozlowski, Marisa C.
supporting information; experimental part, p. 4086 - 4089 (2012/09/22)
An efficient cross-coupling reaction of aryl halides and nitromethane was developed with the use of parallel microscale experimentation. The arylnitromethane products are precursors for numerous useful synthetic products. An efficient method for their direct conversion to the corresponding oximes and aldehydes in a one-pot operation has been discovered. The process exploits inexpensive nitromethane as a carbonyl equivalent, providing a mild and convenient formylation method that is compatible with many functional groups.
