Dear group, I am sending attached the relevant paper for the discussion we just had about step 5 in our Denksport. Buchwald and co-workers first reported the coupling or aryl chlorides with terminal alkynes in Angew. Chemie Int. Ed. 2003. In the attached paper from 2006 they describe very similar conditions for benzyl chloride coupling with terminal alkynes - where they observed selectivity for the benzyl chloride over the aryl chloride. Please adjust the product structure accordingly so that we can continue with this Problem Set in 4 weeks. Thank you for good participation! Best, Nicole