New Synthetic Routes to Z-Shape Functionalized Perylenes

Org. Lett.
http://pubs.acs.org/doi/abs/10.1021/ol3014667

This new synthetic route is useful for making polyaromatic compounds.
Z-shape (1,2,7,8-tetrasubstituted) perylene derivatives are novel chromophores with great potential in various applications. In this communication, the synthesis of a series of Z-shape perylene derivatives via a double Wittig–Knoevenagel benzannulation protocol is reported. Preliminary photophysical and electrochemical studies indicate that the frontier orbital energy levels of these new perylene systems are modulated by electronic, regiochemical, and conformational effects.

Co-delivery of Adipose-Derived Stem Cells and Growth Factor-Loaded Microspheres in RGD-Grafted N-Methacrylate Glycol Chitosan Gels for Focal Chondral Repair

Biomacromolecules

http://pubs.acs.org/doi/abs/10.1021/bm300733n

The coencapsulation of growth factor-loaded microspheres with adipose-derived stem cells (ASCs) within a hydrogel matrix was studied as a potential means to enhance ASC chondrogenesis in the development of a cell-based therapeutic strategy for the regeneration of partial thickness chondral defects. A photopolymerizable N-methacrylate glycol chitosan (MGC) was employed to form an in situ gel used to encapsulate microspheres loaded with bone morphogenetic protein 6 (BMP-6) and transforming growth factor-β3 (TGF-β3) with human ASCs. ASC viability and retention were enhanced when the Young’s modulus of the MGC ranged between 225 and 380 kPa. Grafting an RGD-containing peptide onto the MGC backbone (RGD-MGC) improved ASC viability within the gels. The effects of BMP-6 and TGF-β3 released from the polymer microspheres on ASC chondrogenesis were also assessed.

Synthesis of mikto-topology star polymer containing one cyclic arm

Journal of Polymer Science Part A: Polymer Chemistry

http://onlinelibrary.wiley.com/doi/10.1002/pola.26226/abstract

Well-defined mikto-topology star polystyrene composed of one cyclic arm and four linear arms was synthesized by a combination of atom transfer radical polymerization (ATRP) and Cu-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction.
First, the bromine-alkyne α,ω-linear polystyrenes containing four hydroxyl groups protected with acetone-based ketal groups were synthesized by ATRP of styrene using a designed initiator.
Then, the bromine end-group was converted to the azide and the linear polystyrene was cyclized intra-molecularly by the CuAAC reaction.
The four hydroxyl groups were released by deprotection and then esterified with 2-bromoisobutyryl bromide to produce a cyclic polymer bearing four ATRP initiating units.
By subsequent ATRP of styrene to grow linear polymers with the cyclic polystyrene as a macroinitiator, the mikto-topology star polymers were prepared.

Molecular Engineered Super-Nanodevices: Smart and Safe Delivery of Potent Drugs into Tumors

Advanced Materials

http://onlinelibrary.wiley.com/doi/10.1002/adma.201200954/abstract

A super-nanodevice engineered at molecular level integrates various desired properties in a smart and coordinated way, and can “switch on” or “turn off” certain functionalities as required. Importantly, it can break through complex physiological barriers, and then precisely ferry potent toxic triptolide into tumor cells in vivo, thus significantly maximizing the therapeutic efficacy and reducing the drug toxicity.

Iron-Catalyzed Alkylations of Aryl Sulfamates and Carbamates

Org. Lett.
http://pubs.acs.org/doi/abs/10.1021/ol301681z

The alkylation of aryl sulfamates and carbamates using iron catalysis is reported. The method constructs sp²–sp³ carbon–carbon bonds and provides synthetically useful yields across a range of substrates . The directing group ability of sulfamates and carbamates, accompanied by their low reactivity toward conventional cross-couplings, renders these substrates useful for the synthesis of polyfunctionalized arenes.