Although several methods for the preparation of 4o propargyl indole derivatives have been published, this synthetic transformation is complicated by the tendency of 3o propargyl alcohols to form allenium intermediates in acidic media.  It is therefore a challenge to find an efficient method for the C-3 propargylation of indoles with 3° propargylic alcohols.  In this pa...

We report herein the first synthesis of propargylic alcohols using an organic reducing agent. Diarylbutynol derivatives are formed in moderate to good yields under mild conditions from the reaction of 1-(3-chloroprop-1-ynyl)-4-nitrobenzene with various aromatic aldehydes using tetrakis(dimethylamino)ethylene (TDAE) as reductant.

Similar to propargylic carboxylates and sulphides, 3-propargylindoles undergo 1,2-indole migrations under cationic gold(I) catalysis. The intermediate Au-carbenoid complex may evolve through different pathways depending on the substituents at the propargylic and terminal positions of the alkyne moiety. Thus, 3-indenylindole derivatives were easily obtained through formal iso-Nazarov or Nazarov ...

An efficient synthetic pathway to the possible stereoisomers of skeletally diverse heterocyclic small molecules is presented. The change in shape brought about by different intramolecular cyclizations of diastereoisomeric amino propargylic alcohols is quantified using principal moment-of-inertia (PMI) shape analysis.

A regioselective efficient synthetic approach to N-imino-γ-carbolinium ylides via AgOTf-catalyzed iminoannulation has been developed. This transformation proceeds via a silver(i) triflate-catalyzed consecutive Friedel-Crafts reaction/N-C bond formation sequence between the readily available indole derivatives and propargylic alcohols.

A method to prepare highly conjugated indenes efficiently by iron(III) chloride-catalysed dimerisation of trisubstituted propargylic alcohols under very mild conditions at room temperature is described. The reactions are rapid and operationally straightforward, giving the indene products in good yields and regioselectivity.

An atom-economical diastereoselective synthesis of indenodithiepines and indenodithiocines has been developed via a domino reaction of propargylic alcohols and dithioacetals in the presence of InCl3 as a catalyst. A range of functionalized dithiepines and dithiocines, fused to the indene ring, were obtained in good to excellent yields under mild conditions.