Modular, Gold-Catalyzed Approach to the Synthesis of Lead-like Piperazine Scaffolds
摘要:
Ring-opening of cyclic sulfamidates with propargylic sulfonamides yielded substrates for a gold-catalyzed cyclization to yield tetrahydropyrazines. Manipulation of the tetrahydropyrazines, by reduction or using multicomponent reactions, yielded piperazine scaffolds in which substitution of the carbon atoms was varied. Such scaffolds may have value in the synthesis of novel screening compounds with lead-like molecular properties.
Copper-Catalyzed Borylation of Cyclic Sulfamidates: Access to Enantiomerically Pure (β-and γ-Aminoalkyl)boronic Esters
作者:Nina Ursinyova、Robin B. Bedford、Timothy Gallagher
DOI:10.1002/ejoc.201501492
日期:2016.2
Abstract Cyclicsulfamidates undergo borylation under copper‐catalyzed conditions using B2pin2 to give enantiomerically (and diasteromerically) defined (aminoalkyl)boronicesters. External iodide is essential, but the intermediacy of simple alkyl iodides has been excluded; N‐sulfated intermediates are key in the borylation sequence. Based on stereochemical studies and trapping experiments, the involvement
Spiro-fused Pyrrolidine, Piperidine, and Oxindole Scaffolds from Lactams
作者:Christoph Hirschhäuser、Jeremy S. Parker、Matthew W. D. Perry、Mairi F. Haddow、Timothy Gallagher
DOI:10.1021/ol302176z
日期:2012.9.21
Expedient routes to three classes of novel spiro-fused pyrrolidine, piperidine, and indoline heterocycle scaffolds are described. These three-dimensional frameworks, which conform to the “rule of three”, are suitably protected to allow for site-selective manipulation and functionalization. Different modes of substrate control were explored, which allow for good to excellent levels of diastereoselectivity
Synthesis of 2,6-Disubstituted Piperazines by a Diastereoselective Palladium-Catalyzed Hydroamination Reaction
作者:Brian M. Cochran、Forrest E. Michael
DOI:10.1021/ol702891p
日期:2008.1.1
A highly diastereoselective intramolecular hydroamination is the key step in a modular synthesis of 2,6-disubstituted piperazines. The requisite hydroamination substrates were prepared in excellent yields by nucleophilic displacement of cyclic sulfamidates derived from amino acids. A variety of alkyl and aryl substituents at the 2-position were tolerated. The stereochemistry of the piperazines was determined to be trans by X-ray crystallography, which also showed the preferred conformation of the 2,6-disubstituted piperazine to be a twist-boat due to A(1,3) strain.