Stereoselective Nickel-Catalyzed [2+2+2] Cycloaddition of Enynes and Arynes

Examples of stereoselective reactions of aryne intermediates are rare in the literature. A stereoselective nickel-catalyzed [2+2+2] cycloaddition of 1,6-enynes with aryne intermediates is reported. Excellent stereoselectivities were observed when a substituent is adjacent to the olefin moiety resulting in trans-stereochemistry in the products. This reaction is capable of generating much complexity from simple and readily available starting materials. Furthermore, the products possess a synthetic handle which poises them for further modifications.