ÁLVAREZ GONZÁLEZ , Eleuterio

In the context of palladium-catalyzed guanylation of anilines herein, we have been able to characterize and isolate bis(anilino) and bis(guanidino)Pd(II) complexes using reaction conditions under which stoichiometric amounts of palladium salts are used. Characterization of these palladium complexes strongly supports a mechanistic proposal for...

Reaction of the Ir(iii) dimer [(η 5 -C 5 Me 5 )IrCl 2 ] 2 with PMeXyl 2 (Xyl = 2,6-C 6 H 3 Me 2 ), in the presence of the poorly coordinating base 2,2,6,6-tetramethyl piperidine, gives a chloride complex 1-Cl, resulting from hydrogen chloride elimination involving one of the phosphine benzylic hydrogen atoms and concomitant cyclometallation....

A family of modularly designed chiral bis(1,3,2-diazaphospholidines) with N-aryl substituents (NP-PN) is reported. These compounds have been prepared in two steps from readily available (R,R)-1,2-diaminocyclohexane and tetrachlorodiphosphines. Examples in the set differ in the backbone and the aryl substituents, aiming at their application in...

An efficient route to mixed phosphine / thioglycoside ligands type IV starting from glucose pentaacetate is reported. In only five steps the key epoxide 6 has been obtained in high yield and its structure determined by X-ray analysis. The ring opening of the tert-butyl 4,6-O-benzylidene- 2,3-anhydro-1-thio-β-D-allopyranoside 6 with...

Ligand exchange reactions have been used for the synthesis of metallacyclic complexes of Ni and Pd of the type [M[upper bond 1 start](CH2CMe2-o-C6[upper bond 1 end]H4)(P–N)], where P–N is the phosphinito-imine ligand P(iPr)2OC(Me)[double bond, length as m-dash]N(2,6-C6H3(iPr)2. The protic acid [H(OEt2)(BAr′4)] (Ar′ = 3,5-C6H3(CF3)2) selectively...

The title compound, C15H30N2 2+·2Br−·H2O, was synthesized by reaction of 4-piperidino­piperidine with dibromo­pentane. The dication is built up from three linked piperidine rings, two of which have one quaternary N atom in common (azoniaspiro), whereas the third is N—C bonded to the azoniaspiro system and protonated on the N atom...

The zinc thiodipropionate complex [Zn(tdp)] (1) [tdp = S(CH 2CH2COO)22-] was obtained by reaction of aqueous zinc dichloride with a 1:1 mixture of Na2CO 3 and thiodipropionic acid. The bonding preferences of the tdp anion were studied by DFT methods. The reaction of 1 with o-phenanthroline (phen) gave the dinuclear compound...

The influence of the crystal structure and chemical nature of some ionic liquid/phosphomolybdate hybrids on their catalytic activity in the epimerization of glucose is studied. A clear evidence for structure-activity relationship is found. The inorganic part of the hybrid assures the active sites for the reaction; meanwhile the organic cation...

The Ir(III) pyridylidene TpMe2tiebar above startr(CH2CH2-o-tiebar above endC6H4)(tiebar above startCN(H)CHCHCHtiebar above endCH) (3; TpMe2 = hydrotris(3,5-dimethylpyrazolyl)borate) reacts with oxygen (air), under mild conditions, to afford a bicyclic ether-semiaminal species. The new structure derives formally from two oxidative events. One is...

Electron deficient azides are challenging substrates in CuAAC reactions. Particularly, when N-carbonyl azides are applied the formation of N-carbonyl triazoles has not yet been observed. We report herein the first example of this class of reaction, with a copper-based system that efficiently enables the synthesis of N-carbamoyl 1,2,3-triazoles...

The preparation of new Ru(ii) complexes incorporating fac-coordinated lutidine-derived CNC ligands is reported. These derivatives are selectively deprotonated by tBuOK at one of the methylene arms of the pincer, leading to catalytically active species in the hydrogenation of imines.

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Dialkylmagnesium compounds [MgR2L2] (R = n-Bu, L = none or R = Bn, L = THF) react with 2,6-bis(imino)pyridines (BIP) to afford different types of Mg(II) alkyl complexes, depending on the nature of R. For R = n-Bu, thermally stable products resulting from selective alkyl transfer to the pyridine nitrogen (N1) atom are obtained. However, NMR...

The reaction of 1-alkynes with acyl azides in the presence of [Tpm *,BrCu(NCMe)]BF4 [Tpm*,Br = tris(3,5-dimethyl-4-bromopyrazolyl)methane] as the catalyst provides 2,5-oxazoles in moderate to high yields. This is a novel transformation of the CuAAC type that constitutes a significant variation of the commonly observed [3 + 2] cycloaddition...

Members of a series of iridacyclopentenes of composition [TpMe2Ir(k2-C,C-CH2CR′=CRCH2)(CO)] (TpMe2=hydrotris(3,5-dimethylpyrazolyl)borate; R=R′=H, 1; R=Me, R′=H, 2; R=R′=Me, 3) have been subjected to common organic chemistry procedures for hydrogenation, cyclopropanation, epoxidation, water addition through hydroboration, cis-dihydroxylation,...

The 1,3-dipolar cycloaddition of a variety of aromatic and aliphatic nitrile oxides to 2,5-trans-2,5-diphenylpyrrolidine derived acrylamide and cinnamamide efficiently affords the corresponding 4,5-dihydroisoxazole-5- carboxamides in a highly regio- and stereoselective manner. The cycloaddition of aliphatic nitrile oxides to the analogue...

We report the synthesis and structural characterization of five-coordinate complexes of rhodium and iridium of the type [(η5-C5Me5)M(N^N)]+ (3-M+), where N^N represents the aminopyridinate ligand derived from 2-NH(Ph)-6-(Xyl)C5H3N (Xyl = 2,6-Me2C6H3). The two complexes were isolated as salts of the BArF anion (BArF = B[3,5-(CF3)2C6H3]4). The...

The sequence of reactions ensuing when the 2,6-bis(imino)pyridine Fe(II) dialkyl complexes [Fe(CH2SiMe3)2(BIP)] react with trimethylaluminum is described in detail. The first step is the reduction of the dialkyl to the corresponding monoalkyl complex [Fe(CH 2SiMe3)(BIP)]. In the presence of an excess of trimethylaluminum, these undergo exchange...

Electrophilic, cationic Rh(III) complexes of composition [(η5-C5Me5)Rh(Ap)]+, (1+), were prepared by reaction of [(η5-C5Me5)RhCl2]2 and LiAp (Ap = aminopyridinate ligand) followed by chloride abstraction with NaBArF (BArF = B[3,5-(CF3)2C6H3]4). Reactions of cations 1+ with different Lewis bases (e.g., NH3, 4-dimethylaminopyridine, or CNXyl) led...

Phosphinito-imines, a new class of P,N donors, are readily generated by reaction of bulky arylamide anions [R2CONAr]− (R2 = Me or t-Bu; Ar = 2,6-i-Pr2C6H4) with chlorophosphines ClP(R1)2. In solution, free phosphinito-imines exist in equilibrium with the corresponding amidophosphine tautomers, containing a nitrogen-bound P(R1)2 group. However,...

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph...

Compounds [Bu4N]2[V8O16(oda)4⊂2Cl], 1, [Bu4N]2[V8O16(glut)4⊂2Cl], 2, and [Bu4N][V4O8(glut)2⊂F], 3, (oda = oxydiacetate, O(CH2COO)2 2−; glut = glutarate, CH2(CH2COO)2 2−) were obtained by a stepwise reaction of in situ prepared [Bu4N]VO3 with HCl (or HF for 3) and then with the dicarboxylic acid X(CH2COOH)2 (X = O and CH2), under appropriate...