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[reaction: see text] The nucleophilic substitution of benzylic carbonates with sodium arenesulfinates was catalyzed by the palladium complex generated in situ from [Pd(eta(3)-C(3)H(5))Cl](2) and DPEphos [bis(2-diphenylphosphinophenyl)ether]. The catalytic reaction proceeded in DMSO at 80 degrees C and gave a variety of benzylic sulfones in high yields.

The cross-coupling of benzylic carbonates with arylboronic acids gave the corresponding diarylmethanes in high yields by use of the palladium catalyst generated in situ from [Pd(eta(3)-C(3)H(5))Cl](2) and 1,5-bis(diphenylphosphino)pentane (DPPPent). The Suzuki-Miyaura reaction using DPPPent-palladium catalyst is applicable to syntheses of a broad range of functionalized diarylmethanes. [reaction: see text]

[reaction: see text] N-Tosyl 3-substituted indoles were hydrogenated with high enantioselectivities (95-98% ee) by use of a trans-chelating chiral bisphosphine, (S,S)-(R,R)-PhTRAP ligand. The chiral catalyst, which was generated in situ from [Rh(nbd)(2)]SbF(6), PhTRAP, and Cs(2)CO(3), is useful for enantioselectively synthesizing a range of diverse optically active indolines possessing a chiral carbon at the 3-position.

A palladium complex generated in situ from [Pd(eta3-C3H5)(cod)]BF4 and DPPF is a good catalyst for benzylic alkylation of benzyl methyl carbonate with the carbanion of dimethyl malonates. The catalytic reaction is applicable to a wide range of the benzylations of benzylic esters with malonates. The catalytic activity was heavily affected by the bite angle of the bidentate phosphine ligand on palladium. DPEphos ligand is superior to DPPF in the case of palladium-catalyzed benzylic amination of benzylic esters.

A method for a beam shaping optics is proposed to convert a laser beam profile into required intensity distribution. A beam shaper with aspherical surface is calculated by Snell's law converted from measured irradiate beam profile to required profile. An acrylic resin is cut by a ball type grinding wheel consisted on diamond powder and polished by a cone type felt buff with alumina ceramics powder. A CNC lathe is used to control these tools position. A shaper with 4mm of thickness works to convert multi-mode beam profile with 13mm of diameter into a flat top cylinder with 1mm of diameter. Its working distance is 60mm. Its transmittance is over 98%.It suceed to generate uniform melting mark of 0.6mm diameter on the steel target by YAG laser process.

The transition metal-catalyzed anti-Markovnikov hydroamination of unactivated vinylarenes with a rhodium complex of DPEphos is reported. The reaction of electron-neutral or electron-rich vinylarenes with a variety of secondary amines in the presence of catalyst forms the products from anti-Markovnikov hydroamination in high yields. Reactions of morpholine, N-phenylpiperazine, N-Boc-piperazine, piperidine, 2,5-dimethylmorpholine, and perhydroisoquinoline reacted with styrene to form the amine product in 51-71% yield. Reactions of a variety of vinylarenes with morpholine generated amine as the major product. Reactions of morpholine with electron-poor vinylarenes gave lower amine:enamine ratios than reactions of electron-rich vinylarenes at the same concentration of vinylarene, but conditions were developed with lower concentrations of electron-poor vinylarene to maintain formation of the amine as the major product. Reactions of dimethylamine with vinylarenes were fast and formed amine as the major product. Mechanistic studies on the hydroamination process showed that the amine:enamine ratio was lower for reactions conducted with higher concentrations of vinylarene and that one vinylarene influences the selectivity for reaction of another. A mechanism proceeding through a metallacyclic intermediate that opens in the presence of a second vinylarene accounts for these and other mechanistic observations.

The catalytic asymmetric hydrogenation of α-(acetamido)acrylates was carried out with the rhodium complexes prepared from [Rh(cod)2]BF4 and trans-chelating chiral bisphosphine ligands, (S,S)-2,2′-bis[(R)-1-(dialkylphosphino)ethyl]-1,1′-biferrocenes [(R,R)-(S,S)-TRAPs]. In the reaction of β-unsubstituted or β-monosubstituted α-(acetamido)acrylates [(E)-RCH=C(NHAc)CO2Me], the selectivity for (R)-hydrogenation product increased with decreasing steric demand of the substrate β-substituent and the ligand P-substituent as well as decreasing hydrogen pressure. The selectivity for the (R)-product in the reaction with EtTRAP-rhodium catalyst at 60 °C and 0.5 kg cm-2 of hydrogen pressure was as follows: R = H, 96% ee; R = Me, 92% ee; R = Ph, 77% ee; R = i-Pr, 57% ee. The remarkable steric and pressure effects caused a dramatic reversal of enantioselectivity in the reaction of methyl 2-(N-acetylamino)cinnamate (R = Ph). For example, the selectivity of 87% (R) with EtTRAP at 60 °C and 0.1 kg cm-2 of hydrogen pressure...

The aldol reaction of 2-cyanopropionates with aldehydes proceeded under neutral conditions in the presence of a catalytic amount of the rhodium complex generated in situ from Rh(acac)(CO) 2 and triphenylphosphine, to give the corresponding β-hydroxy-α-cyanocarboxylates bearing a quaternary chiral carbon center at the α-position of the cyano group. A high degree of asymmetric induction for the aldol reaction was achieved by use of trans-chelating chiral diphosphine ligands, ( R , R )-2,2″-bis[( S )-1-(diarylphosphino)ethyl]-1,1″-biferrocenes (TRAPs). The asymmetric aldol reactions gave optically active β-hydroxy-α-cyanocarboxylates with up to 94% ee.

The cross-coupling of benzylic carbonates with arylstannanes proceeded in the presence of [Pd(η3-C3H5)Cl]2–DPPPent catalyst, affording the desired diarylmethanes in good yield.

The nucleophilic substitution of diarylmethyl carbonates with malonate carbanions proceeded in the presence of [Pd(π-C3H5)(cod)]BF4–Cy-Xantphos, giving the desired (diarylmethyl)malonates in up to ...

o-Quinodimethane interemediate was generated from o-[(trimethylsilyl)methyl]benzyl acetate with potassium fluoride. The o-quinodimethane in hand reacted with electron-deficient olefins, affording [...

A ruthenium-catalyzed intermolecular, anti-Markovnikov hydroamination of vinylarenes with secondary aliphatic and benzylic amines is reported. The combination of Ru(cod)(2-methylallyl)2, 1,5-bis(diphenylphosphino)pentane, and triflic acid was the most effective catalyst of those tested. Control reactions conducted without ligand or acid did not form the amine. The reaction of morpholine, piperidine, 4-phenylpiperazine, 4-BOC-piperazine, 4-piperidone ethylene ketal, and tetrahydroisoquinoline with styrene in the presence of 5 mol % of this catalyst formed the corresponding beta-phenethylamine products in 64-96% yield, with 99% regioselectivity, and without enamine side products. Acyclic amines such as n-hexylmethylamine and N-benzylmethylamine reacted with styrene in 63 and 50% yields, respectively. Alkyl-, methoxy-, and trifluoromethyl-substituted styrenes reacted with morpholine in the presence of this catalyst or a related one containing 1,1'-bis(diisopropylphosphino)ferrocene as ligand to give the products in 51-91%. Further, the hydroamination of alpha-methyl styrene was observed for the first time with a homogeneous transition metal catalyst. Preliminary mechanistic studies showed that the reaction occurred by direct, irreversible, anti-Markovnikov hydroamination and that the mechanism of the ruthenium-catalyzed hydroamination is likely to be distinct from that of the recently reported rhodium-catalyzed reaction.

The rhodium complex generated in situ from Rh(acac)(cod) and 2 equivalents of triphenylphosphine is an effective catalyst for hydrogenation of various five-membered heteroaromatic compounds.

Catalytic asymmetric hydrogenation of heteroaromatics had been a formidable issue in organic synthesis. However, the catalytic asymmetric hydrogenation has remarkably progressed during the past decade. This review surveys the recent progress of the asymmetric hydrogenation of 5-membered heteroaromatics, indoles, pyrroles, furans, and benzofurans.

Cross-coupling of benzylic carbonates with heteroarylboronic acids successfully proceeded in the presence of the palladium catalyst that was generated in situ from [Pd(η 3 -C 3 H 5 )Cl] 2 and a chelate bisphosphine DPPPent. Various heteroarylboronic acids were applicable to the catalytic cross-coupling, giving the desired benzylated heteroaromatics in high yields.

trans-Chelating chiral diphosphine TRAP ligands bearing P-aromatic groups are effective for RhI-catalysed asymmetric aldol reaction of 2-cyanopropionates with an aldehyde to give the corresponding aldol adduct with up to 93% ee.