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Abstract: Determination of molecular structural parameters of hydrophobic cholesterol–naphthalimide conjugates for water binding capabilities as well as their moisture‐sensitive supramolecular self‐assembly were revealed. Water binding was a key factor in leading trace water‐induced crystallization against gelation in apolar solvent. Ordered water molecules entrapped in self‐assembly arrays revealed by crystal structures behave as hydrogen‐bonding linkers to facilitate three‐dimensional growth into crystals rather than one‐dimensional gel nanofibers. Water binding was also reflected on the supramolecular chirality inversion of vesicle self‐assembly in aqueous media via heating‐induced dehydration. Structural parameters that favor water binding were evaluated in detail, which could help rationally design organic building units for advancing soft materials, crystal engineering, and chiral recognition. [ABSTRACT FROM AUTHOR]

Abstract: Determination of molecular structural parameters of hydrophobic cholesterol–naphthalimide conjugates for water binding capabilities as well as their moisture‐sensitive supramolecular self‐assembly were revealed. Water binding was a key factor in leading trace water‐induced crystallization against gelation in apolar solvent. Ordered water molecules entrapped in self‐assembly arrays revealed by crystal structures behave as hydrogen‐bonding linkers to facilitate three‐dimensional growth into crystals rather than one‐dimensional gel nanofibers. Water binding was also reflected on the supramolecular chirality inversion of vesicle self‐assembly in aqueous media via heating‐induced dehydration. Structural parameters that favor water binding were evaluated in detail, which could help rationally design organic building units for advancing soft materials, crystal engineering, and chiral recognition. [ABSTRACT FROM AUTHOR]

A 1,2‐dihydrophosphination of bis(phenylphosphino)ethane with a wide range of activated olefins was achieved in a catalytic manner with enantiomeric and diastereomeric excess of up to >99% and 44% respectively. The protocol can be extended to selected substrates leading to free P‐ and C‐chiral 1,2‐diphosphines. The synthesized ligands can also undergo direct complexation onto palladium affording complexes with complete retention of stereo‐integrity. [ABSTRACT FROM AUTHOR]

A novel racemic tertiary amine, 1-(2,5-diisopropylphenyl)-N,N-dimethylethanamine, was synthesizedfrom 2,5-diisopropylbenzaldehyde via a multistep approach in highoverall yield. The ortho palladation of this ligand was found to besensitive to the reaction conditions and the palladating reagentsemployed. The metal complexation process could thus generate a cyclopalladatedcomplex in high yield, lead to an unexpected N-demethylated aminepalladium(II) complex, or both. Both products have been isolated andcharacterized crystallographically in the solid state and spectroscopicallyin solution. The racemic cyclopalladated complex could be efficientlyresolved via the formation of (S)-prolinato derivatives.The absolute stereochemistries of the resolved diastereomeric complexeswere determined by single-crystal X-ray crystallography in the solidstate and by 1H–1H rotating frame Overhausereffect (ROESY) NMR spectroscopy in solution. An evaluation of thesterically hindered resolved cyclopalladated units as chiral auxiliarieswas conducted in the endo-cycloaddition reaction between 3,4-dimethyl-1-phenylphosphole(DMPP) and ethyl vinyl ketone. The two expected phosphanorborneneadducts were generated with moderate stereoselectivity. [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: The organopalladium complex containing ortho-metalated (S)-[1-(dimethylamino)ethyl]naphthalene as the chiral auxiliary has been used as the chiral template to promote the asymmetric cycloaddition reaction between phenyldivinylphosphine and 3,4-dimethyl-1-phenylarsole. The reaction was completed in 1h at room temperature, with the formation of two isomeric cycloadducts in the ratio 1:3. The major phenylvinylphosphino-substituted asymmetrical hetero-bidentate arsanorbornene ligand with chirality residing on both As and P centers was obtained stereoselectively on the chiral palladium template in moderate yield. The chiral heterobidentate ligand was isolated in its enantiomerically pure form by removal of the chiral auxiliary using concentrated hydrochloric acid and subsequent cleavage from the neutral complex [(As–P)PdCl2] by using potassium cyanide. Similar to the earlier reported analogous diphenylphosphino-substituted asymmetrical heterobidentate arsanorbornene (As–P) ligand, an arsenic elimination process was also found in the dichloro and dibromo palladium complex whereas the diiodo species did not show similar reactivity, but the corresponding η2 diiodo complex could be obtained from the η2 dibromo complex by treatment with sodium iodide. [Copyright &y& Elsevier]

Four chiral phosphapalladacycle complexes functionalized with the malonate moiety at the chiral carbon have been synthesized via a consecutive asymmetric hydrophosphination and cyclometallation protocol. High conversions were achieved in the P–H addition reaction, which was itself catalyzed by a phosphapalladacycle. Moderate to good enantioselectivities, were obtained for this step depending on the nature of the functional groups present on the naphthalene backbone. In contrast, the outcome of the subsequent cyclometallation reaction relies highly on the character of the functional groups. The catalytic potential of the synthesized phosphapalladacycle complexes was evaluated in the hydrophosphination reaction of chalcone with moderate results. Four new chiral phosphapalladacycles with designed stereo‐ and electronic properties were prepared by catalysis and by optical resolution and comprehensively characterised. The impact of incorporation of malonate moiety at the chiral carbon and modification of the naphthalene system was studied for the asymmetric hydrophosphination of chalcone. [ABSTRACT FROM AUTHOR]

The first catalytic asymmetric phospha-Michael addition of diphenylphosphine to 4-oxo-enamide using a palladacycle catalyst is developed. [ABSTRACT FROM AUTHOR]

The organopalladium complex containing ortho-metalated ( R )-[1-(dimethylamino) ethyl]naphthalene as the chiral auxiliary has been used as the chiral template to promote the asymmetric hydrophosphination reaction between diphenylphosphine and 2-ethynylpyridine in high selectivity under mild conditions. The double hydrophosphination reaction produces four stereoisomeric products in the ratio of 1:19.4:2.4:1.3. The naphthylamine auxiliary could be removed chemoselectively from the template products by treatment with concentrated hydrochloric acid to form the corresponding chiral dichloro complexes [(P–P)PdCl 2 ]. The molecular structure and absolute configuration of the dichloro complex have been resolved by single-crystal X-ray crystallography. It confirms that the asymmetric diphosphines as P–P bidentate chelate on the chiral naphthylamine palladium templates. Finally, the enantiomerically pure diphosphine ligand with chirality on the carbon backbone can be readily liberated from the dichloro palladium complex as an air-sensitive solid by treatment of the complex with aqueous potassium cyanide in high yield. [ABSTRACT FROM AUTHOR]

Two chiral (–)-diphosphine-digold(I) complexes containing mono- and di- methyl ester substituted diphosphine ligands have been prepared and structurally characterized. Both complexes are highly potent against breast cancer cell line MDA-MB-231 but showed much lower cytotoxicity against the normal human breast epithelial cells MCF10A. When compared with its mono-substituted analogue, the di- methyl ester substituted complex caused markedly lower and relatively insignificant damage to the normal breast cells. The analogous mono- and di- ethyl ester substituted complexes with the same stereochemistry exhibited similar anti-cancer properties but with noticeably higher cytotoxicity against the MCF10A cells. The enantiomeric complex (+)-diphosphine-digold(I) complexes containing the di- methyl ester substituted diphosphine ligand exhibited clearly different biological properties from its (–)-enantiomer. Furthermore, a structurally similar diphosphine-digold(I) complex but in the absence of an ester substituent, killed both the cancerous and the healthy cells indiscriminately. The current study thus revealed that the introduction of multi-esters, particularly methyl esters, is an efficient approach to suppress the side-effects and to improve the efficiency of potential gold-based anti-cancer reagents. When combined with the biological observations, the chirality of gold complexes may serve as a sensitive probe for the future mechanistic studies. [ABSTRACT FROM AUTHOR]

The first asymmetric phospha-Michael addition of diarylphosphines to N-enoyl phthalimides has been developed in the presence of a chiral palladacycle catalyst. A library of free chiral tertiary phosphine adducts were directly obtained with excellent yields and enantioselectivities. Products can be subsequently functionalized to afford β-phosphinoamides, the direct preparation of which from cinnamides has been notoriously challenging. [ABSTRACT FROM AUTHOR]

The utilization of chiral biphosphine oxides as ligand in asymmetric heck reactions of cycloalkenes, furanes, pyranes, and pyrrol systems is presented. [ABSTRACT FROM AUTHOR]

A palladacycle-catalyzed diastereo- and enantioselectivestepwisedouble hydrophosphination of bis(enones) with PhPH2hasbeen developed, allowing intermolecular construction of chiral tertiarybulky P-heterocycles in one pot in high yields. A catalytic cyclefor the reaction is proposed as well. [ABSTRACT FROM AUTHOR]

A chiral palladacycle-promoted enantioselective asymmetrichydrophosphinationof substituted methylidenemalonate esters using diphenylphosphinethat provides direct access to chiral tertiary phosphines is reported.Screening of three easily accessible C,N and C,P palladacycles ascatalysts for this synthetic scenario provided insights into criticalfactors in catalyst design that influence the activation and stereochemistryin Pd(II)-catalyzed asymmetric P–H addition reactions involvingsuch activated substrates. [ABSTRACT FROM AUTHOR]

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 (1,1)- and (1,2)-addition of diphenylphosphine to 3-butyn-2-one and ethyl propiolate can be controlled chemoselectively by regulating the amount of triethylamine as the external base and in the presence of the chiral organopalladium(II) template derived from (R)-N,N-dimethyl-1-(1-naphthyl)ethylamine. [Copyright &y& Elsevier]

A newapproach toward ferrocenyl phosphapalladacycle construction from achiralenones via asymmetric hydrophosphination and subsequent diastereoselectiveC–H activation is described. Its catalytic efficacy towardC–C bond formation is subsequently illustrated. [ABSTRACT FROM AUTHOR]

Optically pure P-chiral 1,2- and 1,3-diphosphines were synthesized chemoselectively and stereoselectively from the chiral organopalladium complex promoted asymmetric Diels–Alder reaction between 3,4-dimethyl-1-phenylphosphole (DMPP) and cis- and trans-ester substituted allylic phosphines. [ABSTRACT FROM AUTHOR]