6783-04-6Relevant articles and documents
XBphos-Rh: A halogen-bond assembled supramolecular catalyst
Carreras, Lucas,Serrano-Torné, Marta,Van Leeuwen, Piet W. N. M.,Vidal-Ferran, Anton
, p. 3644 - 3648 (2018/04/26)
The use of halogen bonding as a tool to construct a catalyst backbone is reported. Specifically, pyridyl- and iodotetrafluoroaryl-substituted phosphines were assembled in the presence of a rhodium(i) precursor to form the corresponding halogen-bonded complex XBphos-Rh. The presence of fluorine substituents at the iodo-containing supramolecular motif was not necessary for halogen bonding to occur due to the template effect exerted by the rhodium center during formation of the halogen-bonded complex. The halogen-bonded supramolecular complexes were successfully tested in the catalytic hydroboration of terminal alkynes.
Imido-hydrido complexes of Mo(IV): Catalysis and mechanistic aspects of hydroboration reactions
Khalimon, Andrey Y.,Farha, Philip M.,Nikonov, Georgii I.
supporting information, p. 18945 - 18956 (2015/11/11)
Imido-hydrido complexes (ArN)Mo(H)(Cl)(PMe3)3 (1) and (ArN)Mo(H)2(PMe3)3 (2) (Ar = 2,6-diisopropylphenyl) catalyse a variety of hydroboration reactions, including the rare examples of addition of HBCat to nitriles to form bis(borylated) amines RCH2N(BCat)2. Stoichiometric reactivity of complexes 1 and 2 with nitriles and HBCat suggest that catalytic reactions proceed via a series of agostic borylamido and borylamino complexes. For complex 1, catalysis starts with addition of nitriles across the Mo-H bond to give (ArN)Mo(Cl)(NCHR)(PMe3)2; whereas for complex 2 stoichiometric reactions suggest initial addition of HBCat to form the agostic complex Mo(H)2(PMe3)3(η3-NAr-HBcat) (16).
Synthesis and reaction chemistry of boryliridium hydride complexes formed by oxidative addition of catecholborane to iridium(I): Lessons for metal-catalyzed hydroboration
Merola, Joseph S.,Knorr, Joseph R.
, p. 86 - 97 (2014/01/06)
The mechanism of catalytic hydroboration was studied through the use of an iridium model complex. Oxidative addition of the B-H bond in (1,2-phenylenedioxy)borane (catecholborane) to (Me3P) 3Ir(COE)(Cl) (COE = cyclooctene) produces mer-(Me3P) 3Ir(Cl)(H)(BO2C6H4) (1). Compound 1 reacted with alkynes to form vinyliridium complexes and will catalyze the hydroboration of alkynes with (1,2-phenylenedioxy)borane. The mechanism of catalytic hydroboration of acetylenes with catecholborane involves: oxidative addition of the B-H bond to the iridium center, followed by chloride dissociation and acetylene coordination, migratory-insertion into the Ir-H bond to form the metallo-vinyl complex, and finally reductive elimination to produce trans-alkylvinylboronate esters. A stable metallo-vinyl complex was produced in the reaction of 1 with dimethylacetylene dicarboxylate and displayed two isomers in solution, one of which showed fluxional behavior. Single crystal X-ray diffraction elucidated a single solid-state structure, but the structures of the isomers in solution and the fluxional properties were studied with NMR spectroscopy and DFT calculations.
An efficient synthesis of 2-(1-(E)-alkenyl)phenylphosphonates via Suzuki reaction of aryl nonaflates with (E)-1-alkenylboronates
Peng, Ai-Yun,Chen, Ba-Tian,Chen, Pei-Jiang
, p. 58 - 62 (2013/06/27)
An efficient and general Suzuki coupling reaction between 2-phosphonylaryl nonaflates and (E)-1-alkenylboronic pinacol esters using Pd(OAc) 2/PPh3 as catalysts, K2CO3 as base and DMF as solvent has been develope
Catalytic hydroboration by an imido-hydrido complex of Mo(iv)
Khalimon, Andrey Y.,Farha, Philip,Kuzmina, Lyudmila G.,Nikonov, Georgii I.
, p. 455 - 457 (2012/01/13)
The imido-hydrido complex (ArN)Mo(H)(Cl)(PMe3)3 catalyses a variety of hydroboration reactions, including the first example of catalytic addition of HBCat to nitriles to form the bis(borylated) amines RCH2N(BCat)2/su
Suzuki-Miyaura cross-coupling of alkenyl tosylates with alkenyl MIDA boronates
Lüthy, Monique,Taylor, Richard J.K.
supporting information; experimental part, p. 3444 - 3447 (2012/08/08)
A practical procedure for the palladium-catalysed Suzuki-Miyaura coupling of various alkenyl tosylates with alkenyl MIDA boronates has been developed. Commercially available trans-bromo[N-succinimidyl-bis(triphenylphosphine)] palladium(II) [Pd(PPh3/
Anomalies in the stereoselectivity of the petasis reaction using styrenyl boronic acids
Churches, Quentin I.,Johnson, James K.,Fifer, Nathan L.,Hutton, Craig A.
scheme or table, p. 62 - 67 (2011/10/05)
The Petasis three-component coupling reaction of N-benzylphenylglycinol, glyoxylic acid, and styrenylboronic acids allows for the efficient synthesis of functionalized homoarylalanine derivatives. The reactions were shown to proceed in high yield but low selectivity, regardless of the nature of the substituent on the styrenylboronic acid component. Anomalies in the stereoselectivity of these reactions compared with previously reported results have been traced to the source of the organoboronic acid. Asymmetric dihydroxylation of the unsaturated amino acid derivatives enables a highly efficient route to dihydroxyhomoarylalanine derivatives. CSIRO 2011.
The active role of NHC ligands in platinum-mediated tandem hydroboration-cross coupling reactions
Lillo, Vanesa,Mata, Jose A.,Segarra, Anna M.,Peris, Eduardo,Fernandez, Elena
, p. 2184 - 2186 (2008/02/08)
Stable N-heterocyclic platinum-carbene complexes are the first example of platinum-mediated regioselective H-B addition to vinylarenes and alkynes, allowing consecutive cross coupling reactions with the same catalytic system. The Royal Society of Chemistry.
Reagent-controlled asymmetric homologation of boronic esters by enantioenriched main-group chiral carbenoids
Blakemore, Paul R.,Marsden, Stephen P.,Vater, Huw D.
, p. 773 - 776 (2007/10/03)
Putative enantioenriched carbenoid species, (R)-1-chloro-2- phenylethylmagnesium chloride (9) and (S)-1-chloro-2-phenylethyllithium (26), generated in situ by sulfoxide ligand exchange from (-)-(Rs,R)-1- chloro-2-phenylethyl p-tolyl sulfoxide (8), effected the stereocontrolled homologation of boronic esters. sec-Alcohols derived from the product boronates by oxidation with basic hydrogen peroxide exhibited % ee closely approaching that of sulfoxide 8 in examples employing Li-carbenoid 26.
CRF RECEPTOR ANTAGONISTS AND METHODS RELATING THERETO
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Page/Page column 30, (2008/06/13)
CRF receptor antagonists are disclosed which may have utility in the treatment of a variety of disorders, including the treatment of disorders manifesting hypersecretion of CRF in a mammals, such as stroke. The CRF receptor antagonists of this invention have the following structure: and pharmaceutically acceptable salts, esters, solvates, stereoisomers and prodrugs thereof, wherein R1, R2n, R5, Ar, and Het are as defined herein. Compositions containing a CRF receptor antagonist in combination with a pharmaceutically acceptable carrier are also disclosed, as well as methods for use of the same.
