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A [(salen)-AlIIICl] complex catalyzes the Passerini three-component reaction of an aldehyde, a carboxylic acid, and an isocyanide to afford alpha -acyloxyamides, e.g., I, with good to excellent enantioselectivity. A variety of nonchelating substrates can b ...
Optically active 1,3-diethynylallenes (DEAs) were prepd. by enantioselective Pd-mediated SN2'-type cross-coupling and their abs. configuration was detd. by X-ray anal. Addn. of tetracyanoethene (TCNE) to donor-substituted DEAs affords novel 1,1,4,4-tetracy ...
We report on a simple method for enhancing the efficiency of photoluminescence (PL) emission from selected chiral forms of semiconducting single-wall carbon nanotubes (SWCNTs). The method is based on the use of a fluorescent dye (Nile blue A) that shows th ...
Using readily available chiral auxiliaries such as (+)- and (-)-camphanic acid, (R,R)- and (S,S)-tartaric acid derivatives (e.g. RADO(R)-COCl, SADO(R)-COCl) efficient diastereoselective syntheses of rare sugars and glycomimetics have been developed. They e ...
(-)-Quinocarcin (I) has been synthesized in a longest linear sequence of 22 steps from 3-hydroxybenzaldehyde in 16% overall yield. The Pictet-Spengler reaction of L-tert-butyl-2-bromo-5-hydroxy phenylalanate, synthesized according to Corey-Lygo's enantiose ...
The aza-MBH reaction of imines, e.g., I, and beta -naphthyl acrylate in the presence of C-6' modified beta -isocupreidine deriv. (0.1 equiv) and beta -naphthol (0.1 equiv) afforded the corresponding (3S)-aza-MBH adducts, e.g., II, in high yield and excelle ...
The ketonitrone 8 was prepared from D-fructose as an inexpensive starting material, and was used in a stereoselective synthesis of 1-deoxymannojirimycin (4), its previously unknown N-hydroxy analogue 15, as well as the polyhydroxylated ketonitrone 14. The ...
At low temperature and in the presence of an acid catalyst, SO2 adds to 1,3-dienes equilibrating with the corresponding 3,6-dihydro-1,2-oxathiin-2-oxides (sultines). These compounds are unstable above -60 degrees C and equilibrate with the more stable 2,5- ...
This paper presents an innovative wing profile featuring an internal truss-like structure of chiral topology. The chiral design is selected because of its unique deformation characteristics, which produce a theoretical, in-plane Poisson's ratio of -1. Such ...
A new tandem reaction leads to bicyclic cyclohexene derivatives with complete control of the relative configuration of the four chiral centers formed. The high diastereoselectivity is the consequence of an endo-selective Diels-Alder reaction followed by an ...
