The synthesis of N-substituted propionyland phenylacetylsubstituted chiral moieties based on the oxazolidin-2-one or 1,3-oxazin-2-one ring systems has been acheived via the use of a variety of different reagents and bases. A 'H NMR spectroscopic study of the prochiral protons Ha and Hb in the methylene group of these systems has been undertaken at 200, 250 and 360 MHz with the aim, of determini...

Chiral molecules with axial or planar chirality are of special interest to synthetic chemists because of both their unique chirality without stereogenic centers and their practical use as chiral auxiliaries or chiral ligands for catalytic asymmetric syntheses. There are therefore a number of reports on the asymmetric synthesis of these chiral molecules. Unlike common chiral molecules with stere...

[reaction: see text] Highly diastereoselective acetate aldol additions using chlorotitanium enolates of mesityl-substituted N-acetyloxazolidinethione and N-acetylthiazolidinethione auxiliaries are reported. These additions proceed in high yields and diastereoselectivities (93:7 to 98:2) for aliphatic, aromatic, and ,-unsaturated aldehydes. Double diastereoselective acetate aldol additions are a...

Saturated aza-heterocycles are highly privileged building blocks that are commonly encountered in bioactive compounds and approved therapeutic agents. These N-heterocycles are also incorporated as chiral auxiliaries and ligands in asymmetric synthesis. As such, the development of methods to functionalize the α-methylene C-H bonds of these systems enantioselectively is of great importance, espec...

Chiral nitrogen-containing compounds are widely distributed in nature and include many biologically important molecules (Chart 1). In these compounds, the nitrogen-containing units are known to play important roles for their bioactivities. For the synthesis of these chiral nitrogen-containing building blocks, use of imines as electrophiles is the most promising and convenient route.1 While many...

This article reviews our contribution in the ®eld of the cobalt(I)-mediated cyclizations. The use of new unsaturated partners such as allenes extend the scope and the utility of the previously developed intramolecular [2‡2‡2] cyclotrimerization. The presence of chiral auxiliaries induced high level of diastereoselectivity in the enediynes cyclization. The discovery of cobalt(I) catalyzed ene-ty...