6287-17-8Relevant articles and documents
Chemoselective and Site-Selective Reductions Catalyzed by a Supramolecular Host and a Pyridine-Borane Cofactor
Morimoto, Mariko,Cao, Wendy,Bergman, Robert G.,Raymond, Kenneth N.,Toste, F. Dean
supporting information, p. 2108 - 2114 (2021/02/06)
Supramolecular catalysts emulate the mechanism of enzymes to achieve large rate accelerations and precise selectivity under mild and aqueous conditions. While significant strides have been made in the supramolecular host-promoted synthesis of small molecules, applications of this reactivity to chemoselective and site-selective modification of complex biomolecules remain virtually unexplored. We report here a supramolecular system where coencapsulation of pyridine-borane with a variety of molecules including enones, ketones, aldehydes, oximes, hydrazones, and imines effects efficient reductions under basic aqueous conditions. Upon subjecting unprotected lysine to the host-mediated reductive amination conditions, we observed excellent ?-selectivity, indicating that differential guest binding within the same molecule is possible without sacrificing reactivity. Inspired by the post-translational modification of complex biomolecules by enzymatic systems, we then applied this supramolecular reaction to the site-selective labeling of a single lysine residue in an 11-amino acid peptide chain and human insulin.
TRANSFORMATION OF ALLYLIC EPOXIDES TO TETRAHYDROFURFURYL ALCOHOLS VIA HYDROBORATION
Zaidlewicz, Marek,Sarnowski, Ryszard
, p. 281 - 284 (2007/10/02)
The allylic epoxides (1)-(4) were transformed to the tetrahydrofurfuryl alcohols (17)-(20), respectively.The formation of (6) and (10) in the hydroboration-oxidation of (4) is interpreted.The monohydroboration-oxidation of (13) and (14) gave (15) and (16), respectively.
