Figure : The Heck reaction of styrene and phenyl chloride in terms of (a) the neutral pathway and (b) the cationic pathway with free energies in kJ/mol adapted from the work of Bäcktorp and Norrby. The highlighted structures (1a-6a) are the post-insertion complexes that forms the basis for the regioselectivity calculations. in the supporting information for detailed flowchart of the procedure). Note that the cis/trans stereochemistry of the βproducts is not specified as this is determined later in the reaction mechanism (see Figure ). Although, the trans isomer is more prevalent among the intermolecular β-products in the Reaxys dataset. The example reaction has the following Reaxys ID: 4892001.