• Iron;
  • Grignard reaction;
  • Sulfur;
  • Homogeneous catalysis;
  • Cross-cou­pling


Alk-2-enesulfonyl chlorides 14 were synthesized by the BCl3-promoted ene reaction of alkenes with SO2. These sulfonyl chlorides were then used as electrophilic partners in iron-catalyzed desulfinylative cross-coupling reactions with different Grignard reagents (aromatic, aliphatic, andheteroaromatic). The reaction can be catalyzed with even 2 mol-% of the simple iron salt Fe(acac)3. The regioselectivity of these allylations was studied by using sulfonyl chlorides 3 and 4 with aryl Grignard reagents. The scope of these allylations was further extended by the coupling of ester-substituted alk-2-enesulfonyl chloride 10 with aromatic Grignard reagents. Symmetrical products were synthesized by double C–C allylation with the use of 2-methylidenepropane-1,3-disulfonyl chloride (12). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)