Scheme 2. The Ni-catalyzed four-component coupling reaction of alkyl fluorides, aryl Grignard reagents, and 1,3-butadiene. Isolated yields. The yields of cross-coupling products 4 are shown in parentheses. ^aca. 20% of 1g was recovered. ^bThe reaction time was 42 h. ^cn.i. = not isolated. ^d44% of 1g was recovered.