rearrangement of propargyl amine salt, in the presence of a base was studied and it was concluded that this occurs through an allenic intermediate.

A facile synthesis of functionally substituted 2-(hetero)aryl 1,3-benzazaphospholes via nickel- or palladium-catalyzed phosphonylation of N-acyl-2-bromoanilides 1a-k with triethyl phosphite is presented. Anilidophosphonates 2a-g with naphthoyl-, o-substituted phenyl, furoyl- or thenoyl groups allow direct reductive cyclization with LiAlH(4) to benzazaphospholes 3. The reaction of the o-bromoder...

In this study four quaternized derivatives of chitosan: trimethyl chitosan (TMC), dimethylethyl chitosan (DMEC), diethylmethyl chitosan (DEMC) and triethyl chitosan (TEC) with degree of substitution of approximately 50+/-5% were synthesized and their effect on the permeability of insulin across intestinal Caco-2 monolayers was studied and compared with chitosan both in free-soluble form and in ...

Conformational studies with quantum chemical methods yielded for the most stable conformer of triethyl amine a propeller-like structure belonging to the point group C(3), which corresponds to an oblate top. The microwave spectrum of this conformer with (14)N hyperfine splitting of all rotational transitions was assigned and molecular parameters were determined. The rotational constants were fou...

Although transfer of electrophilic alkoxyl ("RO+") from organic peroxides to organometallics offers a complement to traditional methods for etherification, application has been limited by constraints associated with peroxide reactivity and stability. We now demonstrate that readily prepared tetrahydropyranyl monoperoxyacetals react with sp(3) and sp(2) organolithium and organomagnesium reagents...

The discovery of coronands and cryptands, organic compounds that can accommodate metal ions in a preorganized two- or three-dimensional environment, was a milestone in supramolecular chemistry, leading to countless applications from organic synthesis to metallurgy and medicine. These compounds are typically prepared via multistep organic synthesis and one of their characteristic features is the...

The daphnane diterpene orthoesters constitute a structurally fascinating family of natural products that exhibit a remarkable range of potent biological activities. Although partial activity information is available for some natural daphnanes, little information exists for non-natural congeners or on how changes in structure affect mode of action, function, potency or selectivity. A gateway str...