Aldrich, a division of Sigma-Aldrich (Nasdaq: SIAL), has released its new "materials by application" Materials Science catalog. The catalog features more than 4,000 products for research in Alternative Energy, Organic Electronics, Metal & Ceramic Science, Nanomaterials, Micro/NanoElectronics and Polymer Science. Each chapter contains technical information and highlights from some of the latest advances in these fields.

"This catalog serves as a materials supply source as well as a tool to assist materials researchers working in the leading areas of modern materials research such as sustainable energy, bio- and soft-materials and electronics and photonics," said Dr. Shashi Jasty, initiative lead for Materials Science at Sigma-Aldrich.

"The structuring of the Aldrich Materials Science catalog is geared toward science and solutions to problems not just traditional materials," said Professor Joachim O. Radler with the Center of NanoScience and Department of Physics at Ludwig-Maximilians University, Munich, Germany. "That's what makes this catalog so valuable."

The printed catalog is a complement to Aldrich's online product catalog, which provides quick access to an easy-to-browse compilation of advanced materials.To request a complimentary copy of the Aldrich Materials Science catalog, please visit http://www.sigma-aldrich.com/mscat or send an email to matsci@sial.com.

Written By: Mark Redlich, Ph.D.

The first total synthesis of the fungal metabolite (+)-wasabidienone B₁ was achieved in 10 steps and 5% overall yield from 1,2,3-trimethoxybenzene.  The key step was an ortho-selective hydroxylative phenol dearomatization (HPD) mediated by stabilized IBX (SIBX), which proceeded cleanly to provide 1:1 diastereomeric mixtures of the target compound and the unnatural (–)-6-epi-wasabidienone B₁.  The target product could be further converted to its congener (–)-wasabidienone B₀ via a thermally induced ring-contracting isomerization in 52% yield.

Pouységu, L. et al. Org. Lett. 2008, 10, 5211.

Written by: Dr. Sharbil J. Firsan

The first catalytic, highly enantioselective synthesis of chiral N-benzoyl hemiaminals has recently been reported by Antilla and co-workers.  Their approach utilizes the direct addition of alcohols to imines derived from aromatic aldehydes, which is facilitated by a BINOL-derived, chiral phosphoric acid organocatalyst.  Some of the attractive features of this method include:

• Good-to-high yields and enantioselectivities
• Mild reaction conditions
• Wide alcohol scope: primary, secondary, tertiary, and cyclic secondary
• A range of substituents in the aryl portion of the imine are tolerated
• Double and triple bonds in the alcohol substrate are compatible with the reaction conditions

(1) Li, G.; Fronczek, F. R.; Antilla, J. C. J. Am. Chem. Soc. 2008, 130, 12216.  (2) For a very recent review on the use of chiral phosphoric acid organocatalysts in asymmetric synthesis, see Adair, G.; Mukherjee, S.; List, B. Aldrichimica Acta 2008, 41, 31

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 Written  by William Sommer, Ph D.

 The Grignard reaction has been around for almost one hundred years and proved to be a powerful tool for the addition of alkyl groups to another molecule. Studte et al, found a clever way to use Grignard reagents for sp³-sp³ coupling. Starting with various á-hydroxy ester triflates, the authors demonstrated enantiocontrol of the Grignard reagent addition using ZnCl₂ as catalyst. The versatility of the method was demonstrated with the reaction of various á-hydroxy ester triflates with various Grignard reagents including secondary acyclic, secondary cyclic, and functionalized reagents. This reaction showed great tolerance in the variation of either reactants with good yields and selectivities. This new reaction offers an alternative to enolate alkylation.

Studte, C.; Breit, B. Angew. Chem., Int. Ed. 2008, 47, 5451.

For those who missed the opportunity in October, due to strong interest the Sigma Aldrich Chemical Synthesis "Did You Know Challenge" will continue through the end of the year with one winner a week being select.  Enter for the chance to win a $250 Aldrich Voucher towards the purchase of Aldrich chemicals, books or labware or a $250 Apple Gift Card. For the people who have already registered your name will continue to be included in the contest.

Sawamura and coworkers have recently disclosed a synthesis of allenylboronates from propargylic carbonates catalyzed by Cu(I). In the presence of Cu(O-t-Bu), Xantphos, and two equivalents of bis(pinacolato)diboron, a variety of substitution patterns and functionalities are tolerated in the transformation, which is believed to proceed through an S_N2´ mechanism. In addition, in the presence of a Lewis acid, the allenylboronates generated are reacted with aldehydes to form homopropargylic alcohols, with reasonable syn selectivity, when relevant.

Ito, H.; Sasaki, Y.; Sawamura, M. J. Am. Chem. Soc. ASAP.