6196-80-1Relevant academic research and scientific papers
Electrophilic Iron Catalyst Paired with a Lithium Cation Enables Selective Functionalization of Non-Activated Aliphatic C?H Bonds via Metallocarbene Intermediates
Hernán-Gómez, Alberto,Rodríguez, Mònica,Parella, Teodor,Costas, Miquel
supporting information, p. 13904 - 13911 (2019/08/30)
Combining an electrophilic iron complex [Fe(Fpda)(THF)]2 (3) [Fpda=N,N′-bis(pentafluorophenyl)-o-phenylenediamide] with the pre-activation of α-alkyl-substituted α-diazoesters reagents by LiAl(ORF)4 [ORF=(OC(CF3)3] provides unprecedented access to selective iron-catalyzed intramolecular functionalization of strong alkyl C(sp3)?H bonds. Reactions occur at 25 °C via α-alkyl-metallocarbene intermediates, and with activity/selectivity levels similar to those of rhodium carboxylate catalysts. Mechanistic investigations reveal a crucial role of the lithium cation in the rate-determining formation of the electrophilic iron-carbene intermediate, which then proceeds by concerted insertion into the C?H bond.
Visible-Light-Promoted Remote C-H Functionalization of o-Diazoniaphenyl Alkyl Sulfones
Du, Shaofu,Kimball, Elizabeth Ann,Ragains, Justin R.
supporting information, p. 5553 - 5556 (2017/10/25)
Visible-light irradiation of ortho-diazoniaphenyl alkyl sulfones in the presence of Ru(bpy)32+ results in remote Csp3-H functionalization. Key mechanistic steps in these processes involve intramolecular hydrogen atom transfer from Csp3-H bonds to aryl radicals to generate alkyl/benzyl radicals. Subsequent polar crossover occurs by single-electron oxidation of the alkyl/benzyl radicals to carbenium ions that then intercept nucleophiles. We have developed remote hydroxylations, etherifications, an amidation, and C-C bond formation processes using this strategy.
Improved syntheses of high hole mobility phthalocyanines: A case of steric assistance in the cyclo-oligomerisation of phthalonitriles
Tate, Daniel J.,Anemian, Remi,Bushby, Richard J.,Nanan, Suwat,Warriner, Stuart L.,Whitaker, Benjamin J.
experimental part, p. 120 - 128 (2012/02/14)
It has been shown that the base-initiated cyclo-oligomerisation of phthalonitriles is favoured by bulky α-substituents making it possible to obtain the metal-free phthalocyanine directly and in high yield. The phthalocyanine with eight α-isoheptyl substituents gives a high time-of-flight hole mobility of 0.14 cm2·V -1·s-1 within the temperature range of the columnar hexagonal phase, that is 169-189 °C.
2-substituted-(2SR)-2-amino-2-((1SR,2SR)-2-carboxycycloprop-1- yl)glycines as potent and selective antagonists of group II metabotropic glutamate receptors. 1. Effects of alkyl, arylalkyl, and diarylalkyl substitution
Ornstein, Paul L.,Bleisch, Thomas J.,Arnold, M. Brian,Wright, Rebecca A.,Johnson, Bryan G.,Schoepp, Darryle D.
, p. 346 - 357 (2007/10/03)
In this paper, we describe the synthesis of a series of α-substituted analogues of the potent and selective group II metabotropic glutamate receptor (mGluR) agonist (1S,1'S,2'S)-carboxy-cyclopropylglycine (2, L-CCG 1). Incorporation of a substituent on the amino acid carbon converted the agonist 2 into an antagonist. All of the compounds were prepared and tested as a aeries of four isomers, i.e., two racemic diastereomers. We explored alkyl substitution, both normal and terminally branched; phenylalkyl and diphenylalkyl substitution; and a variety of aromatic and carbocyclic surrogates for phenyl. Affinity for group II mGluRs was measured using [3H]glutamic acid (Glu) binding in rat forebrain membranes. Antagonist activity was confirmed for these compounds by measuring their ability to antagonize (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid-induced inhibition of forskolin-stimulated cyclic-AMP in RGT cells transfected with human mGluR2 and mGluR3. We found that while alkyl substitution provided no increase in affinity relative to 2, phenylethyl and diphenylethyl substitution, as in 105 and 109, respectively, were quite beneficial. The affinity of 109 was further enhanced when the two aromatic rings were joined by an oxygen or sulfur atom to form the tricyclic xanthylmethyl and thioxanthylmethyl amino acids 113 and 114, respectively. Amino acid 113, with an IC50 of 0.010 μM in the [3H]Glu binding assay, was 52-fold more potent than 2, whose IC50 was 0.47 μM.
Enantioselective synthesis of α-methyl carboxylic acids using a DiTOX chiral auxiliary
Page, Philip C. Bulman,McKenzie, Michael J.,Allin, Steven M.,Klair, Sukhbinder S.
, p. 13149 - 13164 (2007/10/03)
Five α-methyl carboxylic acids have been prepared with high e.e.s using 1,3-dithiane 1-oxide (DiTOX) units as the stereocontrolling elements and sources of chirality.
Tritium-Labeled Enantiomers of Disparlure. Synthesis and in Vitro Metabolism
Prestwich, Glenn D.,Graham, Steven McG.,Kuo, Jing-Wen,Vogt, Richard G.
, p. 636 - 642 (2011/07/06)
Both of the enantiomers of disparlure, the gypsy moth sex attractant, have been prepared at high specific activity (58 Ci/mmol) by homogeneous tritiation of the optically active alkenyl oxiranes.An improved preparation of the racemic disparlure is also described.The radiolabeled epoxides are cleanly converted to a single product by enzymes isolated from adult gypsy moths (Lymantria dispar).Enzymatic activity obtained from male antennae showed the highest conversion; enzymes isolated from female antennae and from male and female legs showed lower activity.The identification of the metabolite as the threo-7,8-diol is established by independent synthesis and by chemical derivatizations to the diacetate, n-butylboronate, and bis(trimethylsilyl) ether.A symmetrical epoxide analogous to disparlure is converted to a diol product at a significantly lower rate.
