Reductive lithiation of alkoxy-substituted benzyl methyl ethers and connection with cross-coupling reactions

2-and 4-Ethoxymethoxybenzyl methyl ethers were employied as useful starting materials for the synthesis of 1,2- or 1,4-dicarbo-substituted benzenes. The proposed reaction sequence involves connection between the reductive lithiation of benzyl alkyl ethers and the metal-catalyzed cross-coupling reaction of aromatic triflates.     

Application of the anionic homologous Fries‐rearrangement to the synthesis of 3‐alkylbenzofuran‐2(3H)‐ones

We have developed an effective organometallic‐based procedure allowing the employment of 2‐methylphenols as easily available starting materials in the synthesis of 3‐alkylbenzofuran‐2(3H)‐ones. The first step of this protocol, an anionic homologous Fries‐rearrangement, afforded 2‐(2‐ tert ‐butyldimethylsilyloxyaryl)acetamides, which were selectively metalated and monoalkylated at the benzylic position. Acidic work‐up of crude products afforded the desired heterocycles in satisfactory overall yields. Copyright © 2008 John Wiley & Sons, Ltd.     

High-resolution direct patterning of gold nanoparticles by the microfluidic molding process

A novel microfluidic molding process was used to form microscale features of gold nanoparticles on polyimide, glass, and silicon substrates. This technique uses permeation pumping to pattern and concentrate a nanoparticle ink inside microfluidic channels created in a porous polymer template in contact with a substrate. The nanoparticle ink is self-concentrated in the microchannels, resulting in dense, close-packed nanoparticle features. The method allows for better control over the structure of printed features at a resolution that is comparable to inkjet printing, and is purely additive with no residual layers or etching required. The process uses low temperatures and pressures and takes place in an ambient environment. After patterning, the gold nanoparticles were sintered into continuous and conductive gold traces.     

Injection molded microfluidic chips featuring integrated interconnects

An injection molding process for the fabrication of disposable plastic microfluidic chips with a cycle time of 2 min has been designed, developed, and implemented. Of the sixteen commercially available grades of cyclo-olefin copolymer (COC) that were screened for autofluorescence and transparency to ultraviolet (UV) light, Topas 8007 x 10 was identified as the most suitable for production. A robust solid metal mold insert defining the microfluidic channels was rapidly microfabricated using a process that significantly reduces the time required for electroplating. No wear of the insert was observed even after over 1000 cycles. The chips were bonded by thermal fusion using different bonding conditions. Each condition was tested and its suitability evaluated by burst pressure measurements. The COC microfluidic chips feature novel, integrated, reversible, standardized, ready-to-use interconnects that enable operation at pressures up to 15.6 MPa, the highest value reported to date. The suitability of these UV transparent, high pressure-resistant, disposable devices was demonstrated by in situ preparation of a high surface area porous polymer monolith within the channels.