40679-84-3Relevant academic research and scientific papers
Palladium-catalyzed allylic C-H amination of alkenes with N-fluorodibenzenesulfonimide: Water plays an important role
Xiong, Tao,Li, Yan,Mao, Lujia,Zhang, Qian
, p. 2246 - 2248 (2012/03/27)
A new palladium-catalyzed highly regioselective allylic C-H amination of alkenes with NFSI in the presence of a catalytic amount of water was developed and successfully expanded to Selectfluor-mediated palladium-catalyzed aminations of alkenes with N-tosy
Photochemical transformations of proteinogenic and non-proteinogenic amino acids
Griesbeck, Axel G.
, p. 272 - 283 (2007/10/03)
The photochemistry of N-activated enantiomerically pure α-amino acids is described with emphasis on chemo-, regio-, stereo-, and spin selectivity. An especially valuable chromophore is the phthalimido group. The first excited singlet states are short-lived and deactivated (chemically) via homolytic CH cleavage or (physically) via electron-transfer steps. The first excited triplet states are chemically deactivated via electron-transfer reactions and subsequent deprotonation/coupling steps. A wide variety of product types were synthesized, and potential target molecules were available by tuning the reaction conditions. Also remote groups can be activated by means of electron-transfer steps, which represents an attractive new synthetic protocol for macrocyclization.
Photochemistry of N-phthaloyl derivatives of electron-donor-substituted amino acids
Griesbeck,Henz,Hirt,Ptatschek,Engel,Loffler,Schneider
, p. 701 - 714 (2007/10/02)
The hydroxy substituted amino acids threonine and serine have been investigated concerning their photochemical behaviour when activated as N-phthaloyl substrates. The methyl esters 1a and 2a solely underwent cleavage of the central C-C single bond to give the glycine derivative 3 and an aldehyde fragment. C-unprotected threonine derivative 1b is converted into a series of products the composition of which depends on solvent polarity and on the electronic state. Three reaction modes were detected for the N-phthaloyl derivatives of the aryl substituted amino acids phenylalanine, tyrosine, and dihydroxyphenylalanine (DOPA): (A) decarboxylation (only for 12a), (B) β-fragmentation, and (C) ring enlargement reaction. Processes B and C are initiated by photo electron transfer (PET), as the solvent dependence revealed. The DOPA derivatives 14a and 14b are the most prominent examples due to their exclusive PET reactivity leading to type C products (18a,b) with high diastereoselectivity (90:10). PET results from the first excited singlet states of 12 and 13, whereas for compounds 14 the corresponding triplet states are involved. The correlation between photochemical reactivity and the fluorescence decay data for compounds 12a,b and 15 is discussed.
