A gold-catalysed enantioselective Cope rearrangement of achiral 1,5-dienes

Gold(I)-Catalyzed Desymmetrization of 1,4-Dienes by an Enantioselective Tandem Alkoxylation/Claisen Rearrangement.

An enantioselective alkoxylation/Claisen rearrangement reaction was achieved by a strategic desymmetrization of 1,4-dienes under the catalysis of (S)-DTBM-Segphos(AuCl)2/AgBF4. This reaction system was highly selective for the formation of 3,3-rearrangement products, providing cycloheptenes with various substitutions in good yield and good to excellent enantioselectivity. This transformation wa...

Gold(I)-catalyzed enantioselective [4 + 2]-cycloaddition of allene-dienes.

An enantioselective gold(I)-catalyzed intramolecular [4 + 2]-cycloaddition of allenes and dienes is reported. The reactions allow for the asymmetric synthesis of trans-hexahydroindenes and pyrrolidine products using C(3)-symmetric phosphitegold(I) and ortho-arylphosphoramiditegold(I) complexes as catalysts, respectively.

Gold(I)-catalysed [1,3] O→C rearrangement of allenyl ethers.

A simple and rapid access to the α-substituted acryl aldehydes has been provided by developing a gold-catalysed [1,3] rearrangement of the allenyl ethers importantly with a record turnover frequency of 4600 h(-1) (at 0.05 mol% of the catalyst concentration) in homogeneous gold(I) catalysis.

Antarafacial-Antarafacial Cope Rearrangement

Thermal rearrangement of 2-thiabicyclo[ 3.2.0]hepta-3,6-diene-6,7-dicarbonitriles 1-3 to their 4,5-dicarbonitrile isomers 4-6 takes place at 110-140 "C in yields of 82-84%. The reactions are first order with rates almost independent of the polarity of the solvent. Activation parameters (m = 120-140 kJ mol-' and AS* = 0 J K-l mol-') are in agreement with a concerted symmetry-allowed antarafacial...

Enantioselective adsorption in achiral zeolites.