2008

September 23, 2008

Intramolecular Anodic Olefin Coupling Reactions: The Use of a Nitrogen Trapping Group

Hai-Chao Xu and Kevin D. Moeller*

J. Am. Chem. Soc., 2008, 130 (41), pp 13542–13543

Anodic olefin coupling reactions using a tosylamine trapping group have been studied. The cyclizations are favored by the use of a less-polar radical cation and more basic reaction conditions. The most significant factor for obtaining good yields of cyclic product is the use of the more basic reaction conditions. The cyclizations allow for the rapid synthesis of substituted proline derivatives.

 

August 5, 2008

Microelectrode Arrays and Ceric Ammonium Nitrate: A Simple Strategy for Developing New Site-Selective Synthetic Methods

David Kesselring, Karl Maurer and Kevin D. Moeller
J. Am. Chem. Soc., 2008, 130 (34), 11290–11291

Conditions for a site-selective ceric ammonium nitrate oxidation have been developed. The reactions proceed nicely on both 1K- and 12K-microelectrode arrays. The procedure for developing the reactions was very simple and demonstrated that the same reagents used for a solution-phase reaction can be used for a related site-selective reaction on a microelectrode array.

 

July 25, 2008

Moving Known Libraries to an Addressable Array: A Site-Selective Hetero-Michael Reaction

Melissae Stuart, Karl Maurer, Kevin D. Moeller
Bioconj. Chem. 2008, 19, 1514-1517

A two-step, Michael reaction-based strategy for site-selectively placing molecules by unique electrodes in an addressable microelectrode array has been developed. The strategy is compatible with the use of polypeptide nucleophiles and works with microelectrode arrays having either 1024 electrodes/cm2 or 12544 electrodes/cm2. The chemistry should allow for the transfer of existing molecular libraries to microelectrode array devices for analysis.

 

May 21, 2008

Building Addressable Libraries: Site-Selective Formation of an N-Acyliminium Ion Intermediate

David Kesselring, Karl Maurer and Kevin D. Moeller
Org. Lett., 2008, 10 (12), 2501–2504

A strategy for site-selectively generating reactive N-acyliminium ion intermediates on a microelectrode array has been developed. The route capitalizes on the use of an electroauxiliary for building a methoxylated amino acid substrate, and then the electrochemical generation and solution phase confinement of acid in order to form the N-acyliminium ion. Keys to this strategy were the stability of an N-α-methoxyalkyl amide to basic reaction conditions and the generality of the electrogenerated acid conditions for conducting microelectrode array reactions in a site-selective fashion.

 

April 26, 2008

The Use of a Detectable, Mass-spectrometry-cleavable Linker for Quality Control on an Addressable Microelectrode Array

Ceng Chen, Peng Lu, Amy Walker, Karl Maurer, and Kevin D. Moeller
Electrochem. Commun., 2008, 10, 973–976

The synthesis, site-selective placement, and TOF-SIMS cleavage properties of a new, fluorescent linker for attaching molecules to a microelectrode array are reported. The linker was developed to provide a handle for quality control assessment of the microelectrode arrays being used to probe the binding of molecular libraries with biological receptors.

 

April 15, 2008

Anodic Cyclization Reactions and the Synthesis of (−)-Crobarbatic Acid

Hai-Chao Xua, John D. Brandta and Kevin D. Moeller
Tetrahedron Letters, 2008, 49(24), 3868-3871

A synthesis of (−)-crobarbatic acid is reported along with the first use of a vinyl-substituted ketene dithioacetal as a coupling partner for an anodic cyclization reaction. The use of the vinyl-substituted ketene dithioacetal enables the construction of a cyclic product having a tetrasubstituted carbon with a relative stereochemistry opposite to that originally obtained from the cyclization.