Synthesis and Electronic Structure of Bis(imino)pyridine Iron Metallacyclic Intermediates in Iron-Catalyzed Cyclization Reactions
摘要:
The bis(imino)pyridine iron dinitrogen compound, ((PDI)-P-iPr(TB))Fe(N-2)(2) ((iPr(TB)) PDI = 2,6-(2,6-Pr-i(2)-C6H3- N=C center dot(CH2)(3))(2)(C5H1N)) is an effective precatalyst for the [2 pi + 2 pi] cycloaddition of diallyl amines as well as the hydrogenative cyclization of N-tosylated enynes and diynes. Addition of stoichiometric quantities of amino-substituted enyne and diyne substrates to ((PDI)-P-iPr(TB))Fe(N-2)(2) resulted in isolation of catalytically competent bis(imino)pyridine iron metallacycle intermediates. A combination of magnetochemistry, X-ray diffraction, and Mossbauer spectroscopic and computational studies established S = 1 iron compounds that are best described as intermediate-spin iron(III) (S-Fe = 3/2) antiferromagnetically coupled to a chelate radical anion (S-PDI = 1/2). Catalytically competent bis(imino)pyridine iron diene and metallacycles relevant to the [2 pi + 2 pi] cycloaddition were also isolated and structurally characterized. The combined magnetic, structural, spectroscopic, and computational data support an Fe(I) Fe(III) catalytic cycle where the bis(imino)pyridine chelate remains in its one-electron reduced radical anion form. These studies revise a previous mechanistic proposal involving exclusively ferrous intermediates and highlight the importance of the redox-active bis(imino)pyridine chelate for enabling catalytic cyclization chemistry with iron.
Cyclisation of α,ω-dienes promoted by bis(indenyl)zirconium sandwich and ansa-titanocene dinitrogen complexes
作者:Doris Pun、Donald J. Knobloch、Emil Lobkovsky、Paul J. Chirik
DOI:10.1039/c1dt10149h
日期:——
Metallation of a variety of α,ω-dienes has been explored with an η9,η5-bis(indenyl)zirconiumsandwich compound and an ansa-titanocene dinitrogen complex. The η9,η5-bis(indenyl)zirconiumsandwich compound, (η9-C9H5-1,3-Pr2)(η5-C9H5-1,3-iPr2)Zr, served as an isolable source of Negishi's reagent and readily formed a kinetic mixture of cis and trans diastereomers of the corresponding zirconacyclopentanes
PYRIDAZINONE COMPOUNDS AND P2X7 RECEPTOR INHIBITORS
申请人:Shigeta Yukihiro
公开号:US20100286390A1
公开(公告)日:2010-11-11
Novel pyridazinone compounds of formula (I), which inhibit the purinergic P2X7 receptor and are useful for prevention, therapy and improvement of inflammatory and immunological diseases.
Electronic Structure Determination of Pyridine N-Heterocyclic Carbene Iron Dinitrogen Complexes and Neutral Ligand Derivatives
作者:Jonathan M. Darmon、Renyuan Pony Yu、Scott P. Semproni、Zoë R. Turner、S. Chantal E. Stieber、Serena DeBeer、Paul J. Chirik
DOI:10.1021/om500727t
日期:2014.10.13
acceptor and the iron being viewed as a hybrid between low-spin Fe(0) and Fe(II) oxidation states. This electronic description has been supported by spectroscopic data and DFT calculations. Addition of N,N-diallyl-tert-butylamine to (iPrCNC)Fe(N2)2 yielded the corresponding iron diene complex. Elucidation of the electronic structure again revealed the CNC chelate acting as a π acceptor with no evidence for
Abrasive, abrasive set, and method for polishing substrate
申请人:HITACHI CHEMICAL COMPANY, LTD.
公开号:US10030172B2
公开(公告)日:2018-07-24
A polishing agent comprises: a fluid medium; an abrasive grain containing a hydroxide of a tetravalent metal element; a first additive; a second additive; and a third additive, wherein: the first additive is at least one selected from the group consisting of a compound having a polyoxyalkylene chain and a vinyl alcohol polymer; the second additive is a cationic polymer; and the third additive is an amino group-containing sulfonic acid compound.
Methods to induce targeted protein degradation through bifunctional molecules
申请人:Dana-Farber Cancer Institute, Inc.
公开号:US10464925B2
公开(公告)日:2019-11-05
The present application provides bifunctional compounds which act as protein degradation inducing moieties. The present application also relates to methods for the targeted degradation of endogenous proteins through the use of the bifunctional compounds that link a cereblon-binding moiety to a ligand that is capable of binding to the targeted protein which can be utilized in the treatment of proliferative disorders. The present application also provides methods for making compounds of the application and intermediates thereof.