Synthesis and characterization of poly(thioether ether sulfone imide)s derived from isomeric bis(chlorophthalimide)s and bis(4-mercaptophenyl) sulfone

A series of isomeric bis(chlorophthalimide)s (BCPIs) were conveniently prepared from 3-chlorophthalic anhydride, 4-chlorophthalic anhydride, and mixtures thereof. Polymerization of BCPIs with bis(4-mercaptophenyl) sulfone (BMPS) proceeded smoothly in the presence of tributylamine, from which a class of isomeric poly(thioether ether sulfone imide)s (PTESIs) with inherent viscosities of 0.45-0.82 dL/g were obtained. The solubility, thermal stability, and mechanical properties of these polymers were characterized. Compared to the PTESIs derived from single BCPIs, i.e., 3,3′-, 3,4′-, or 4,4′-BCPIs, the PTESIs derived from mixed BCPIs showed better solubility and higher storage modulus. These PTESIs also demonstrated good thermal stability, giving only 5% weight loss at temperature of 490 °C in nitrogen atmosphere. The glass transition temperatures (T_gs) of these isomeric PTESIs were between 242 and 265 °C, and were increased with increasing of the ratio of 3-chlorophthalimide unit in the polymer backbone.     

Preparation of planar‐chiral multidonor phosphanylferrocene carboxamides and their application as ligands for palladium‐catalysed asymmetric allylic alkylation

Amide coupling of (S_p)‐2‐(diphenylphosphanyl)ferrocene‐1‐carboxylic acid with appropriate terminal amines mediated by 1‐hydroxybenzotriazole and a carbodiimide affords multi‐donor amides terminally functionalized with planar‐chiral (S_p)‐2‐(diphenylphosphanyl)ferrocen‐1‐yl moieties in good to excellent yields. Palladium catalysts based on these ligands efficiently promote asymmetric allylic alkylation of 1,3‐diphenylallyl acetate with in situ generated dimethyl malonate anion to give the C‐alkylated product with ees up to 93% at room temperature. Copyright © 2010 John Wiley & Sons, Ltd.     

Radical ring‐opening polymerization of five‐membered cyclic vinyl sulfone using p‐toluenesulfonyl halides

Radical ring‐opening polymerizations of a five‐membered cyclic vinyl sulfone monomer, 2‐vinylthiolane‐1,1‐dioxide (VTDO), was carried out by using p‐toluenesulfonyl iodide (TosI) and bromide (TosBr) as radical initiators, and the corresponding ring‐opened polymer (PVTDO) was obtained. Both TosI and TosBr were found to work as the radical initiators for the polymerization of VTDO in bulk. The use of TosI gave PVTDOs with a broad, multimodal distribution of molecular weight in low yields. When 10 mol % of TosBr was employed, the isolated yield of PVTDO reached 49%, and the obtained PVTDO had a relatively narrow, monomodal molecular weight distribution of 1.8 with an M_n of 4100. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Photoinduced depolymerization of poly(olefin sulfone)s possessing photobase generator side‐chains: Effect of spacer‐chain length

Photoinduced depolymerization of poly(olefin sulfone)s possessing photobase generators in the side‐chain was investigated. Irradiation with UV light generated base on the side‐chains and induced depolymerization based on proton abstraction on the main‐chain. The effect of the length of the spacer chain, which connects the photobase‐generating moiety to the polymer main chain on the photoinduced depolymerization, also was investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3873–3880     

Short communication: Stille coupling reactions of functionalized triorganotin halides

Convenient conditions for the Stille coupling of halide‐bearing triorganotin compounds, which do not normally react under typical Stille reaction conditions, are presented. The coupling of vinylstannanes with allyl bromide using palladium(II) catalysis is accomplished under fluoride assistance to give the substituted 2,5‐hexadien‐1‐ols in Z‐configuration. Copyright © 2004 John Wiley & Sons, Ltd.     

A [Pd (η3‐PhCHCHCHPh)(phosphino‐oxazoline)]+ complex with almost identical P‐ and N‐trans influences. 13C chemical shifts and allylic alkylation chemistry

The Pd‐catalysed enantioselective allylic alkylation of a 1,3‐diphenylallyl substrate using a bulky phosphinooxazoline auxiliary leads to a relatively small enantiomeric excess of 66%. The ca 30% loss, relative to related P,N‐auxiliaries, is rationalized by (a) the presence of additional isomers, (b) a dynamic equilibrium between two of these as shown by exchange spectroscopy and (c) the identification of one exchanging diastereomer in which there is almost no difference between the two terminal allyl ¹³C chemical shifts, i.e. these P‐ and N‐donors reveal an almost identical trans influence. Copyright © 2002 John Wiley & Sons, Ltd.