Enantioenriched bifunctional crotylsilanes for the asymmetric synthesis of orthogonally protected 2-methyl-1,3-diols.

Enantiomerically pure α-substituted crotylsilane reagents I and ent-I undergo asymmetric aldehyde crotylation followed by Ir(I)-catalyzed diastereoselective allylic etherification to give a variety of orthogonally protected 2-methyl-1,3-diols at the synthetically useful level of yields and stereoselectivity. The reagents are air-stable and bifunctional so that they can be used in these reactions sequentially without recourse to functional group adjustments.

Air-stable bifunctional allylation reagents for the asymmetric synthesis of differentiated syn- and anti-1,3-diols.

Turning the diols: Enantiomerically pure bifunctional reagents I and ent-I undergo asymmetric aldehyde allylation followed by Ir(I)-catalyzed enantioselective decarboxylative allylic etherification to give differentiated syn- and anti-1,3-diols with complete control of the absolute and relative stereochemistry (see scheme; PMP = para-methoxyphenyl, dbcot = dibenzo[a,e]cyclooctatetraene, DBU = 1,8-diazabicyclo[5.4.0]undec-7-ene).

Concise asymmetric synthesis of orthogonally protected syn- and anti-1,3-aminoalcohols.

Novel chiral binfunctional reagents V and ent-V undergo asymmetric aldehyde allylation followed by Ir(I)-catalyzed enantioselective allylic amidation to give orthogonally protected syn- and anti-1,3-aminoalcohols with complete control of absolute and relative stereochemistry. The Mitsunobu reaction of the initial homoallylic alcohol products followed by Ir(I)-catalyzed enantioselective allylic amidation provides orthogonally protected syn- and anti-1,3-diamine derivatives in high yields and with excellent stereoselectivities.

Ir(I)-catalyzed enantioselective decarboxylative allylic etherification: a general method for the asymmetric synthesis of aryl allyl ethers.

Ir(I)-catalyzed enantioselective decarboxylative allylic etherification of aryl allyl carbonates provides aryl allyl ethers. Key to the generality and high stereoselection of the reaction is the use of the intramolecular decarboxylative allylation process and [Ir(dbcot)Cl](2) as an Ir(I) source. Ir(I)-catalyzed diastereoselective decarboxylative allylic etherification, combined with asymmetric aldehyde crotylation and cross metathesis, can furnish monoprotected 2-methyl-1,3-diols (starting from simple aldehydes) with high diastereoselectivities.

Complete quantification of group A and group B soyasaponins in soybeans.

A combination of high-pressure extraction and preparative chromatography was used to purify the group A and group B soyasaponins from soy germ for use as analytical standards and for use in biological assays. A standardized sample preparation and extraction method was developed for the analysis of phytochemicals found in soy and processed soy products, which is reproducible in other laboratories. The extracts can be analyzed with standard liquid chromatography-mass spectrometry and high-performance liquid chromatography methods to identify and quantitate the group A and group B forms of the soy saponins, as well as the soy isoflavones.

Determination of modafinil in plasma and urine by reversed phase high-performance liquid-chromatography.

Modafinil (Provigil) is a new wake-promoting drug that is being used for the management of excessive sleepiness in patients with narcolepsy. It has pharmacological properties similar to that of amphetamine, but without some of the side effects associated with amphetamine-like stimulants. Since modafinil has the potential to be abused, accurate drug-screening methods are needed for its analysis.