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Readily-available triarylphosphines are explored as organocatalysts for the hydroarsination reaction. When compared to transition metal catalysis, phosphine organocatalysis greatly improved solvent compatibility of the hydroarsination of nitrostyrenes. Upon complete conversion, arsine products were isolated in up to 99% yield while up to 48% of the phosphine catalyst was still active. A mechanism was proposed and structure-activity analysis regarding catalyst activity concluded that sterically-bulkier catalysts were effective at minimizing catalyst deactivation. Image 1 • Air-stable triarylphosphine catalysts for the hydroarsination reaction. • Catalysis compatible with non-alcoholic solvents. • Arsine-mediated phosphine oxidation observed. • Organophosphine catalysis mechanistically different from transition metal catalysis. [ABSTRACT FROM AUTHOR]

Abstract The ruthenacyclic carbamoyl complexes [Ru (2-NHC(O)C 5 H 4 N) (CO) 2 (X) (NCMe)] (X = Cl, Br) (1) and [Ru (2-NHC(O)C 5 H 4 N) (CO) 2 (2-S-Py)] (2) undergo substitution reactions with organophosphines to afford derivatives which are prone to a redistribution of the phosphine ligand. We have studied these redistribution reactions experimentally and computationally, and proposed an essentially common reaction pathway. The results suggest that the carbamoyl ligand exerts a very strong trans effect. Graphical abstract Image 1 Highlights • Phosphine derivatives of ruthenacyclic carbamoyls prone to redistribution of the phosphine ligand. • Weakening of Ru-P bond due to very strong trans effect of carbamoyl ligand. • Proposed pathway involves a 16-electron intermediate. [ABSTRACT FROM AUTHOR]

Abstract: Cyano-functionalized allylic phosphine substrates containing the ortho-metalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary were synthesized from bromoacetaldehyde dimethylacetal via a one-pot process. The diastereoselective hydrophosphination reactions of the cis- and trans-allylic phosphine substrates gave the cyano-functionalized chiral 1,2-bis(diphenylphosphino)ethane products with high yield and stereoselectivity. The subsequent organic transformation reactions of the cyano-substituted products chemoselectively afforded the formyl- and hydroxyl-functionalized chiral 1,2-diphosphine complexes with retention of stereochemistry. The coordination properties and absolute configurations of the novel 1,2-diphosphine complexes were established by single crystal X-ray crystallography. The optically pure 1,2-bis(diphenylphosphino)ethane ligands with cyano-, formyl- and hydroxyl-functionalities could be liberated in high yields from the corresponding dihalo palladium complexes by treatment with aqueous potassium cyanide. [Copyright &y& Elsevier]

Abstract: An organopalladium complex containing orthometalated (R)-(1-(dimethylamino)ethyl)naphthalene as the chiral auxiliary has been used to promote the asymmetric hydroalkoxylation reactions between weak nucleophile methanol and 1,1-bis(diphenylphosphino)ethylene or 1,1-bis(diphenylphosphino)ethylene monoxide in good regio- and stereo-selectivities in the presence of an external base. The major addition product obtained from methanol and 1,1-bis(diphenylphosphino)ethylene monoxide was subsequently isolated in a quantitative yield in its configurationally pure form and characterized by means of two-dimensional rotating-frame nuclear Overhauser enhancement (ROESY) NMR spectroscopy as well as single crystal X-ray diffraction analysis. The enantiomerically pure bis-phosphine monoxide ligand was subsequently liberated in high yield. [ABSTRACT FROM AUTHOR]

Abstract: An organopalladium(II) complex derived from (S)-N,N-dimethyl-1-(1-naphthyl)-ethylamine was employed as the chiral auxiliary to promote the asymmetric hydrophosphination reactions between diphenylphosphine and (E) or (Z)-diphenylphosphinostyrene in high regio- and stereoselectivities at low temperature with triethyl amine as external base. Optically active free ligand (R)-1,2-bis(diphenylphosphino)-1-phenylethane was obtained in high yield subsequently. Mechanistic pathways explaining the stereoselectivity of the chiral organopalladium template promoted hydrophosphination reactions are also proposed. [Copyright &y& Elsevier]

Abstract: The organopalladium complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]naphthalene as the chiral template was employed to promote the asymmetric cycloaddition reaction between 3,4-dimethyl-1-phenylarsole and diphenylvinylphosphine. It has been proven that the chiral template incorporating napthylamine is more efficient than the benzylamine based analogue as evidenced by the drastic improvement in stereoselectivity and reaction rate. However, when no chiral template was employed, trans-[PdI2(3,4-dimethyl-1-phenylarsole)2] reacted with trans-[PdI2(diphenylvinylphosphine)2] producing a structurally novel diiodo complex, as a result of an interesting selective cleavage of one As–C bond in the norbornene skeleton and subsequent rearrangements within the skeletal framework. The molecular structure of the diiodo product has been confirmed by X-ray crystallography. Structural analysis showed that in addition to the normal As–P five-membered ring, there is one new five-membered ring containing As–O bond being formed during the course of the reaction along with another seven-membered ring incorporating a hydroxy group. [Copyright &y& Elsevier]

• Reactions of osmostibine precursor Os 2 (CO) 8 (µ 3 -SbPh)Os(CO) 3 (Cl) 2 (1) under TMNO activation. • Mono-, di-, tri- and tetra-substituted derivatives with PPh 3 and CH 3 CN isolated. • First substitution occurs at the Os(CO) 3 Cl 2 "spike"; shuts down release of osmostibine. • CH 3 CN-substituted osmostibine generated in situ by reaction of bis-acetonitrile derivative of 1 with CO and trapped with W(CO) 5 (NCCH 3). Derivatisation of the osmium carbonyl cluster Os 2 (CO) 8 (µ 3 -SbPh)Os(CO) 3 (Cl) 2 , 1 , the precursor to the metalloligand Os 2 (CO) 8 (µ -SbPh), 2 , was explored as a route to derivatives of the latter. The reaction of 1 with PPh 3 in different stoichiometries and under trimethylamine N-oxide activation in CH 3 CN led to mono-, di-, tri- and tetra-substitution by PPh 3 and CH 3 CN. The first substitution occurred at the Os(CO) 3 Cl 2 "spike" and although subsequent substitution favoured CH 3 CN at the osmostibine moiety, the latter was not readily displaced by PPh 3. Substitution at the "spike" also shut down release of the substituted osmostibine. The CH 3 CN-substituted osmostibine could, however, be generated in situ through the bis-acetonitrile derivative of 1 by conversion of the Os(CO) 2 (NCCH 3)Cl 2 "spike" back into its removable Os(CO) 3 Cl 2 form through reaction with CO gas, and was then trapped with W(CO) 5 (NCCH 3). [ABSTRACT FROM AUTHOR]

The first example of an enantioselective hydrophosphination reaction of ethenesulfonyl fluoride derivatives catalyzed by a phosphapalladacycle afforded chiral sulfonyl fluoride-derived phosphines in quantitative yields and enantioselectivities of up to 93% ee. Investigations revealed the importance of adjacent vacant sites within the active metal center for intramolecular nucleophilic attack to provide the functionalized phosphine. Image 1 • Asymmetric hydrophosphination reaction accessing phosphinosulfonyl fluorides. • Excellent yields and enantioselectivities for most substrates. • Ability to generate free phosphines from the catalytic protocol. • Importance of adjacent vacant sites within the active center of the catalyst. [ABSTRACT FROM AUTHOR]