6143-71-1Relevant articles and documents
Iridium-Triggered Allylcarbamate Uncaging in Living Cells
Gupta, Ajay,Gupta, Shalini,Mahawar, Pritam,Prasad, Puja,Sasmal, Pijus K.,Singh, Neelu
supporting information, p. 12644 - 12650 (2021/09/06)
Designing a metal catalyst that addresses the major issues of solubility, stability, toxicity, cell uptake, and reactivity within complex biological milieu for bioorthogonal controlled transformation reactions is a highly formidable challenge. Herein, we report an organoiridium complex that is nontoxic and capable of the uncaging of allyloxycarbonyl-protected amines under biologically relevant conditions and within living cells. The potential applications of this uncaging chemistry have been demonstrated by the generation of diagnostic and therapeutic agents upon the activation of profluorophore and prodrug in a controlled fashion within HeLa cells, providing a valuable tool for numerous potential biological and therapeutic applications.
Asymmetric hydrogenation of ketones using a ruthenium(II) catalyst containing BINOL-derived monodonor phosphorus-donor ligands
Xu, Yingjian,Alcock, Nat W.,Clarkson, Guy J.,Docherty, Gordon,Woodward, Gary,Wills, Martin
, p. 4105 - 4107 (2007/10/03)
(Chemical Equation Presented) A series of ruthenium(II) complexes containing BINOL-based monodonor phosphorus ligands have been prepared and applied to the asymmetric catalysis of the hydrogenation of aryl/alkyl ketones. The best ligands for this application are those which contain an aromatic groups with either a methoxide or bromide on the ortho position. Using these ligands, alcohols with ee's of up to 99% are formed.
Highly efficient phosphapalladacyclic catalysts for the hydroarylation of norbornene
Brunel, Jean Michel,Heumann, Andreas,Buono, Gerard
, p. 1946 - 1949 (2007/10/03)
Exceptionally high turnover numbers of up to 196 x 106 moles of product per mole of catalyst, turnover frequencies of up to 12 x 106 moles of product per mole of catalyst per hour, and yields of 98% were achieved in the hydroarylatio
Asymmetric synthesis of (S,S)-(+)-1,1′-bis-(methyl-phenyl-phosphino) ferrocene
Kaloun,Merdes,Genet,Uziel,Juge
, p. 455 - 463 (2007/10/03)
The asymmetric synthesis of 1,1′-bis-(methyl-phenyl-phosphino) ferrocene 1 is described using the oxazaphospholidine borane complex 5 as synthon. Two strategies were investigated, based either on P-C bond formation by ring opening of complex 5 with the 1,1′-dilithio ferrocene 10, or on homocoupling of the cyclopentadienyl-methyl-phenyl-phosphine borane 2 anion with FeCl2. The first leads to a diastereomeric mixture of the diphosphine 1 in a 55:45 ratio, and the low stereoselectivity is explained by the steric hindrance of the ferrocene dianion. In the second strategy, the (R)-cyclopentadienyl phosphine borane 2 (85% ee) was prepared by the reaction of CpNa with the optically active chlorophosphine borane 14, derived from the aminophosphine borane 6a. The coupling of 2 leads to the 1,1′-diphosphino ferrocene borane 13, which is obtained diastereomerically pure by recrystallization, then decomplexed to the corresponding (S,S)-diphosphine 1.
The Mechanism of Double Olefination Using Titanium-Substituted Ylides
Reynolds, Kelly A.,Finn
, p. 2574 - 2593 (2007/10/03)
The adduct 3, derived from TiCl3(OiPr) and (Me2N)3P=CH2, engages in a complicated set of interactions with NaN(SiMe3)2 and aldehydes, resulting in the requirement to use excess amounts of both reagents for the one-pot synthesis of allenes. When TiCl2(OiPr)2 is used instead, ligand substitution reactions with NaN(SiMe3)2 are diminished and so stepwise transformations can be accomplished without excess amounts of each reagent. The selective production of vinylphosphonium salts and byproduct titanium oxides from Ti-substituted ylides and aldehydes is proposed to arise from the presence of a chloride leaving group on the metal. Isolated vinylphosphonium compounds may be deprotonated with phenyllithium to give thermally sensitive allenic phosphoranes, which have been characterized by low temperature multinuclear NMR. The reaction of allenic phosphoranes with aldehydes affords oxaphosphetane and betaine intermediates which appear to interconvert upon warming to produce allene and phosphine oxide. Dimethylamino-substituted phosphorus components are required for high yields in both steps of the allene-forming process, presumably to boost the reactivity of the hindered Ti-substituted ylide reagents and to stabilize the allenic phosphorane unit so that it may be trapped by aldehyde. The placement of chiral groups on the phosphorus methylide or aldehyde components results in low levels of enantiomeric and diastereomeric induction, respectively, during allene formation. In two cases, the diastereomeric ratios of initially-formed oxaphosphetanes have been found to differ from the diastereomeric composition of their product allenes, offering examples of the phenomenon known as "stereochemical drift". However, oxaphosphetane/betaine formation from allenic phosphorane and aldehyde has been found to be irreversible, suggesting that an intramolecular betaine olefin isomerization is responsible for the loss of stereochemical integrity during the Wittig step.
A flexible, highly efficient method for the preparation of homochiral oxazaphospholidine-boranes
Sheehan, Susan Kult,Jiang, Meiqun,McKinstry, Lydia,Livinghouse, Tom,Garton, Donna
, p. 6155 - 6162 (2007/10/02)
An efficient and operationally simple procedure for the synthesis of 2-substituted 3,4-dimethyl-5-phenyloxazaphospholidine derivatives has been developed. This new method permits the large scale preparation of a range of electronically and sterically diff
The ortho Matallation of N,N,N',N'-Tetramethyl-P-phenyl-phosphonothioic Diamide
Craig, Donald C.,Roberts, Nicholas K.,Tanswell, Janine L.
, p. 1487 - 1496 (2007/10/02)
The reaction of C6H5P(S)(NMe2)2 (2) with BuLi in diethyl ether/hexane mixture gives the ortho-metallated species o-LiC6H4P(S)(NMe2)2 (3), which has been characterized by 31P and 13C n.m.r. spectroscopy, and by preparation of the derivatives Ro-C6H4P(S)(N
Reaktionen koordinierter Liganden V. Pentacarbonylhalogenaminophosphinkomplexe (CO)5MPRXNR'2 durch Umsetzung von (CO)5MPR(NR'2)2 mit Halogenwasserstoff
Diemert, K.,Kuchen, W.,Lorenzen, D.
, p. 17 - 32 (2007/10/02)
Aminophosphines RP(NR'2)2 (R = Ph, cyclo-Hex, (-)-Men, t-Bu; R' = Me, Et) as ligands L in complexes (CO)5ML (M = Cr, Mo, W) have been found to react with HX (X = Cl, Br) mainly under substitution of only one of the two dialkylamino groups by halogen.Under similar conditions the free phosphines are converted into the dihalogenphosphines.The halogenamino complexes (CO)5MPRXNR'2 are readily accessible by this reaction, the mechanism of which is discussed.The preparation of several new compounds RP(NR'2)2 is reported.
SYNTHESE UND SPEKTROSKOPISCHE CHARAKTERISIERUNG VON CYCLOPENTADIENYLEISEN-KOMPLEXEN MIT P-N-LIGANDEN DES TYPS (C6H5)3-nP(NR2)N (n = 0-3; R = CH3, C2H5)
Schumann, Hans
, p. 169 - 178 (2007/10/02)
The complex cations BF4 (L = (C6H5)3-nP(NR2)n; n = 0-3; R = CH3, C2H5) have been obtained from the reaction of BF4 (I) with L.The reaction of I with E(NR2)3 (E = As, Sb; R = CH3) is also described.Spectroscopic investigations (IR, 1H, 13C and 31P NMR) indicate an increase in electron density on the iron center through increase of the number of P-bound NR2 groups.
Etude par la resonance de l'azote 15 et du phosphore 31 de la liaison P-N dans des derives du phosphore trivalent; analyse statistique des donnees experimentales
Gouesnard, Jean-Paul,Dorie, Jean,Martin, Gerard J.
, p. 1295 - 1304 (2007/10/02)
Natural abundance 15N and 31P nmr and dynamic 13C nmr have been applied to the study of about fifty aminophosphines, in order to generalize the influence of the chemical factors which govern the electronic distribution of the nitrogen-phosphorus III bond.