A novel method for the preparation of 2,6-disubstituted benzenesulfonates and benzenesulfonyl chlorides utilizing the powerful alkyl sulfonate ortho directing group

(-)-Sparteine-mediated metalation of ferrocenesulfonates. The first case of double asymmetric induction of ferrocene planar chirality

[reaction: see text] A new process for induction of planar chirality via a matched chiral-directed metalation group (DMG)/(-)-sparteine interaction is demonstrated. Thus, s-BuLi metalation of (-)-menthylferrocenesulfonate (8b) with (-)-sparteine constitutes a matched pair resulting in amplification of the dr in the 2-formyl product 10a.

Synthesis and biological activity of enantiomeric pairs of phosphosulfonate herbicides

The phosphosulfonates are a new class of soil-active herbicides which control a variety of annual grass and broadleaf weeds. Chirality at the phosphorus atom afforded the opportunity to explore stereospecific requirements for herbicidal activity. Chiral (hydroxymethyl)phosphinate intermediates were enzymatically resolved (Pseudomonas fluorescens lipase) from the racemic mixtures and then used to prepare two pairs of enantiomeric phosphosulfonates. Biological testing of the enantiomeric phosphosulfonate herbicides demonstrated that, in each case, the herbicidal activity was attributed to the (+) enantiomer and that the (+) enantiomer is more active than the racemate.