A simple one-pot synthesis of phosphinoselenoic amides and diamides from secondary phosphine selenides and amines using Et3N-CCl4

The multi-component reaction between secondary phosphine selenides and amines (primary, secondary, and primary diamines) proceeds using the Et₃N-CCl₄ system under mild conditions to give phosphinoselenoic amides or diamides in 81-89% isolated yields.     

Reaction of secondary phosphine selenides with the system Se/MOH (M = Li, Na, K, Rb, Cs): A novel three-component synthesis of diorganodiselenophosphinates

Secondary phosphine selenides, R₂P(Se)H (R = PhCH₂CH₂, PhCH(Me)CH₂, 4-t-BuC₆H₄CH₂CH₂, NaphthylCH₂CH₂, Ph), react with the system Se/MOH (M = Li, Na, K, Rb, Cs) in the system THF/EtOH at ambient temperature unusually fast (20–30 s) to give cleanly and almost quantitatively (in 94–100% yield) earlier unknown diorganodiselenophosphinates of alkali metals.     

Radical addition of secondary phosphine sulfides and selenides to vinyl tellurides

The regiospecific addition of secondary phosphine sulfide and phosphine selenide to alkyl vinyl tellurides proceeds under radical initiation (AIBN, 65–70 °C, 2.5–3.5 h) to afford the anti-Markovnikov adducts, (2-alkyltellanylethyl)phosphine chalcogenides, in 86–99% yields.     

Enantioselective addition of phenyl and alkyl acetylenes to imines catalyzed by chiral Cu(I) complexes

The stereoselective addition of phenyl acetylene and alkyl acetylenes to imines, catalyzed by chiral bis-imines-Cu(I) complexes was studied. A very simple experimental procedure allowed to obtain at room temperature optically active propargyl amines in very good yields and enantioselectivity up to 81%.     

Synthesis of functionalised cyclohexadienes through addition of lithiated phosphine borane complexes to benzonitriles

Functionalised 1,3- and 1,4-cyclohexadienes have been prepared through dearomatisation of benzonitriles by sequential conjugate addition of -lithium alkyl(diphenyl)phosphine borane in the presence of HMPA and capture of the intermediate anion with protonating and alkylating reagents.     

Formation of a PIII−C(sp2) bond by addition of diphenyl(trimethylsilyl)phosphine to activated acetylenes

Diphenyl(trimethylsilyl)phosphine reacts with alkoxy(alkyl)acetylenes to give mixtures of addition products, (2-alkoxy-2-trimethylsilylalkenyl)diphenylphosphines and (2-alkoxyalkenyl)diphenylphosphines. The reaction is sensitive to the solvent; in MeCN, it gives only nonsilylated products. (1-Alkoxyethenyl)diphenylphosphines were obtained as the main products upon the reaction of Ph₂PSiMe₃ with terminal alkoxyalkynes, irrespective of the reaction conditions. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1792–1796, September, 1998.     

Reaction of functionalised thiols with oligoisobutenes via free-radical addition.: Some new routes to thermoplastic crosslinkable polymers

The functionalisation of vinylidene (isopropenyl) terminated oligoisobutenes (polyisobutenes; PIB) with several thiols has been realised in the presence of free-radical generators. Oxygen (air) is a significant accelerator for this reaction and in some cases, alone, is sufficient to cause the reaction to occur. Free-radicals were generated from peroxydicarbonates, AIBN or UV irradiation. The reaction is of an anti-Markovnikov type with the RS-function adding to the vinylidene CH₂ group selectively in the presence of more substituted olefin groups in commercial PIB. A variety of thiols has been investigated and the synthesis of elastomeric polymers resulting from the hydrolysis and condensation of a trialkoxysilane coupled to PIB via a sulphide link has been demonstrated. The synthesis of comb-like polymers made by the addition of PIB to poly(mercaptopropyl methylsiloxane) has been achieved in a way to leave some non-reacted thiol functions available for crosslinking. A perfluoroalkyl thiol modified PIB shows a significant reduction in surface tension compared to the starting PIB polymer.     

A novel simple synthesis of bis(diorganoselenophosphoryl)selenides (R2PSe)2Se from secondary phosphines and elemental selenium

Secondary phosphines R₂PH [R = Ph(CH₂)₂, 4-t-BuC₆H₄(CH₂)₂, 4-MeOC₆H₄(CH₂)₂, 2-Naphth(CH₂)₂] react with two equivalents of elemental selenium under mild conditions (85 °C, 3 h, toluene) to afford bis(diorganoselenophosphoryl)selenides (R₂PSe)₂Se in high yields (75-92%).     

Catalyst-free addition of secondary phosphine chalcogenides to pyrazolecarbaldehydes

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The synthesis of a [2.2]paracyclophane-derived secondary phosphine oxide and a study of its reactivity

A planar chiral secondary phosphine oxide based on [2.2]paracyclophane was synthesized and its chemistry investigated; it was shown to be a competent pre-ligand in palladium(0)-mediated reactions, and displayed promising activity in gold(I)-catalysed cyclisations. The secondary phosphine oxide could be transformed into a collection of P-stereogenic tertiary phosphine oxides. These are rare examples of the planar chirality of [2.2]paracyclophane being combined with a P-stereogenic centre. Unfortunately, epimerisation of the phosphorus stereocentre during reduction limits the use of this chemistry.     

Nucleophilic addition of 2-hydroxyquinoxaline to acetylenes

Vinylation of 2-hydroxyquinoxaline affords either 2-vinyloxyquinoxaline or 1-vinyl-2-quinoxalone depending on the reaction conditions. The reactions of 2-hydroxyquinoxaline with 3-phenylprop-2-ynonitrile or 4-hydroxyalk-2-ynonitriles yield 3-phenyl-3-(quinoxalyl-2-oxy)prop-2-enonitrile or 4-hydroxy-3-(quinoxalyl-2-oxy)alk-2-enonitriles, respectively. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 738–741, April, 2000.     

Synthesis of new halo-containing acetylenes and their application to the synthesis of azoles

The convenient synthesis of ten halo- and an isoxazole-containing acetylenes from the reaction of acetylenes with n-butyl lithium and subsequent reaction with an electrophile agent (ethyl trichloroacetate, ethyl dichloroacetate, trifluoroacetic anhydride, 3-methylisoxazol-5-carbonyl chloride, carbon tetrachloride and 1,1,1-trifluoro-4-ethoxy-3-buten-2-one) in moderated to good yields is reported. The application of 1,1,1-trichloro-4-phenyl-3-butyn-2-one on the synthesis of two azoles is also showed.     

Conjugate addition of aromatic amines to ethenetricarboxylates

The conjugate addition of amines is considered to be a useful reaction in synthetic organic chemistry. The reaction of reactive electrophilic olefins, ethenetricarboxylates, and aromatic amines with and without catalytic Lewis acids such as ZnCl₂ and ZnBr₂ at room temperature gave amine adducts in high yields. The products were converted to α-amino acid, dl-aspartic acid derivatives. Using Lewis acids such as Sc(OTf)₃ and Zn(OTf)₂ at higher temperature (40-80 °C), the reaction of ethenetricarboxylates and N-methylaniline gave an aromatic substitution product. A catalytic enantioselective conjugate addition using a chiral Lewis acid was also investigated. For example, the reaction of 1,1-diethyl 2-tert-butyl ethenetricarboxylate with N-methylaniline in the presence of chiral bisoxazoline-Cu(II) complex in THF at −20 °C for 17 h gave an amine adduct in 91% yield and 78% ee. On the other hand, the reaction with aniline and primary aniline derivatives gave adducts with almost no ee%.     

Oxidative addition of different electrophiles with rhodium(I) carbonyl complexes of unsymmetrical phosphine–phosphine monoselenide ligands

Dimeric chlorobridge complex [Rh(CO)₂Cl]₂ reacts with two equivalents of a series of unsymmetrical phosphine–phosphine monoselenide ligands, Ph₂P(CH₂)_nP(Se)Ph₂ {n = 1( a ), 2( b ), 3( c ), 4( d )}to form chelate complex [Rh(CO)Cl(P∩Se)] ( 1a ) {P∩Se = η²‐(P,Se) coordinated} and non‐chelate complexes [Rh(CO)₂Cl(P～Se)] ( 1b–d ) {P～Se = η¹‐(P) coordinated}. The complexes 1 undergo oxidative addition reactions with different electrophiles such as CH₃I, C₂H₅I, C₆H₅CH₂Cl and I₂ to produce Rh(III) complexes of the type [Rh(COR)ClX(P∩Se)] {where R = ? C₂H₅ ( 2a ), X = I; R = ? CH₂C₆H₅ ( 3a ), X = Cl}, [Rh(CO)ClI₂(P∩Se)] ( 4a ), [Rh(CO)(COCH₃)ClI(P～Se)] ( 5b–d ), [Rh(CO)(COH₅)ClI‐(P～Se)] ( 6b–d ), [Rh(CO)(COCH₂C₆H₅)Cl₂(P～Se)] ( 7b–d ) and [Rh(CO)ClI₂(P～Se)] ( 8b–d ). The kinetic study of the oxidative addition (OA) reactions of the complexes 1 with CH₃I and C₂H₅I reveals a single stage kinetics. The rate of OA of the complexes varies with the length of the ligand backbone and follows the order 1a > 1b > 1c > 1d . The CH₃I reacts with the different complexes at a rate 10–100 times faster than the C₂H₅I. The catalytic activity of complexes 1b–d for carbonylation of methanol is evaluated and a higher turnover number (TON) is obtained compared with that of the well‐known commercial species [Rh(CO)₂I₂]^?. Copyright © 2006 John Wiley & Sons, Ltd.     

Chemoselective noncatalytic addition of secondary phosphine chalcogenides to citral

Addition of secondary phosphine oxides, phosphine sulfides and phosphine selenides to 3,7-dimethyl-2,6-octadienal (citral) (48–50°C, THF, argon) proceeds exclusively to the aldehyde group giving rise to new polyfunctional tertiary phosphine chalcogenides with diene and hydroxyl moieties in high preparative yield (up to 80%).     

Stereoselective double addition of chiral alkynyl-zincs to cobalt-stabilized acetylenedicarbaldehyde

Acetylenedicarbaldehyde, a desirable but intractable C₄ synthon, can be protected as the Gorgues’ dicobalt hexacarbonyl complex. It undergoes chimio-, diastereo- and enantioselective attack of terminal alkynes using zinc triflate and (−)-N-methyl-ephedrine to afford stable complexes of chiral secondary carbinol-skipped oligoynes.     

Solvent-free palladium-catalyzed addition of diaryl dichalcogenides to alkynes

Solvent-free palladium-catalyzed addition of diaryl disulfides and diselenides to terminal alkynes makes it possible to achieve high stereoselectivity and almost 100% yields in 10 min using only 0.1 mol.% catalyst. Both Pd(PPh₃)₄ and easily available Pd(OAc)₂ and PdCl₂ can be used in the reaction with an excess of triphenylphosphine. The catalyst and triphenylphosphine are readily recycled for repeated use. The study of the mechanism of the solvent-free catalytic reaction indicates that the process involves binuclear palladium complexes.