Peter Knops

High dilution reactions — New synthetic applications

The chemistry of medio- and macrocycles experienced an impetuous development during the past years, especially through the increasing significance of supramolecular chemistry [1] which was valued in 1987 by awarding the Nobel Prize to Pedersen, Cram, and Lehn [2].

The first internally functionalized chiral [2.2]metacyclophanes

The new medium membered heterocycles (2c–i), additionally strained due to internal substituents, could be obtained after optimization of a simple one-step cyclisation reaction; the barrier of the restricted rotations of the phenyl ring in (2h) and of the t-butyl group in (2i) were measured; the X-ray, NMR, and CD data of the stable enantiomers of (2c–i) are compared with those of the less strained parent skeleton (2a).