63314-77-2Relevant academic research and scientific papers
Enantioselective Reactions of 2-Sulfonylalkyl Phenols with Allenic Esters: Dynamic Kinetic Resolution and [4+2] Cycloaddition Involving ortho-Quinone Methide Intermediates
Chen, Ping,Wang, Kai,Guo, Wengang,Liu, Xianghui,Liu, Yan,Li, Can
supporting information, p. 3689 - 3693 (2017/03/21)
We report herein a dynamic kinetic resolution (DKR) involving ortho-quinone methide (o-QM) intermediates. In the presence of Et3N and the cinchonine-derived nucleophilic catalyst D, the DKR of 2-sulfonylalkyl phenols with allenic esters afforded chiral benzylic sulfones in 57–79 % yield with good to excellent enantioselectivity (85–95 % ee). Furthermore, with 2-(tosylmethyl)sesamols or 2-(tosylmethyl)naphthols, from which stable o-QM substrates can be generated, a formal [4+2] cycloaddition delivered 4-aryl- or alkyl-substituted chromans with excellent enantioselectivity (88–97 % ee).
Iridium-catalyzed borylation of secondary benzylic C-H bonds directed by a hydrosilane
Cho, Seung Hwan,Hartwig, John F.
supporting information, p. 8157 - 8160 (2013/07/05)
Most functionalizations of C-H bonds by main-group reagents occur at aryl or methyl groups. We describe a highly regioselective borylation of secondary benzylic C-H bonds catalyzed by an iridium precursor and 3,4,7,8-tetramethyl-1, 10-phenanthroline as the ligand. The reaction is directed to the benzylic position by a hydrosilyl substituent. This hydrosilyl directing group is readily deprotected or transformed to other functional groups after the borylation reaction, providing access to a diverse set of secondary benzylboronate esters by C-H borylation chemistry.
Iridium-catalyzed arene ortho -silylation by formal hydroxyl-directed C-H activation
Simmons, Eric M.,Hartwig, John F.
, p. 17092 - 17095 (2011/03/01)
A strategy for the ortho-silylation of aryl ketone, benzaldehyde, and benzyl alcohol derivatives has been developed in which a hydroxyl group formally serves as the directing element for Ir-catalyzed arene C-H bond activation. One-pot generation of a (hyd
Targeting the gatekeeper residue in phosphoinositide 3-kinases
Alaimo, Peter J.,Knight, Zachary A.,Shokat, Kevan M.
, p. 2825 - 2836 (2007/10/03)
A single residue in the ATP binding pocket of protein kinases-termed the gatekeeper-has been shown to control sensitivity to a wide range of small molecule inhibitors (Chem. Biol. 2004, 11, 691; Chem. Biol. 1999, 6, 671). Kinases that possess a small side chain at this position (Thr, Ala, or Gly) are readily targeted by structurally diverse classes of inhibitors, whereas kinases that possess a larger residue at this position are broadly resistant. Recently, lipid kinases of the phosphoinositide 3-kinase (PI3-K) family have become the focus of intense research interest as potential drug targets (Chem. Biol. 2003, 10, 207; Curr. Opin. Pharmacol. 2003, 3, 426). In this study, we identify the residue that corresponds structurally to the gatekeeper in PI3-Ks, and explore its importance in controlling enzyme activity and small molecule sensitivity. Isoleucine 848 of p110α was mutated to alanine and glycine, but the mutated kinase was found to have severely impaired enzymatic activity. A structural bioinformatic comparison of this kinase with its yeast orthologs identified second site mutations that rescued the enzymatic activity of the I848A kinase. To probe the dimensions of the gatekeeper pocket, a focused panel of analogs of the PI3-K inhibitor LY294002 was synthesized and its activity against gatekeeper mutated and wild-type p110α was assessed.
