PtCl₂‐Catalyzed Tandem Enyne Cyclization/1,2 Ester Migration Reaction Controlled by Substituent Effects of All‐Carbon 1,6‐Enynyl Esters

Abstract

On the move: A novel PtCl2-catalyzed tandem 1,6-enyne cyclization/1,2-acyloxy migration reaction was developed, which was shown to be controlled by substitution effects. Using this method, a series of substituted enol esters containing the cyclopentenyl motif were prepared in moderate to high yields.

Gold(I)-Catalyzed Activation of Alkynes for the Construction of Molecular Complexity

“…Propargylic carboxylates react with gold­(I) complexes undergoing 1,2- or 1,3-acyloxy migrations through 5- exo -dig or 6- endo -dig cyclizations to form α-acyloxy-α,β-unsaturated carbenes 345 or allene-gold complexes 347 , which are in equilibrium (Scheme ). , Similar transformations have been described for propargyl acetals, as well as by using other metal catalysts …”

Rhodium‐Catalyzed Formylation of Unactivated Alkyl Chlorides to Aldehydes

“…While the palladium‐catalyzed formylation of the latter substrates has been developed to some extent, [1] alkyl halides remained basically unknown as starting materials. Apart from stoichiometric multi‐step transformations (Scheme 1 a),[ 2 , 3 , 4 , 5 ] catalytic reductive formylations of alkyl iodides and bromides are only known using either platinum complexes or radical reactions (Scheme 1 b). [ 6 , 7 ] More specifically, in 1986 Watanabe and co‐workers published a platinum complex catalyzing the formylation of alkyl iodides to give the corresponding aldehydes at high pressure of syn gas (50 bar).…”