A new and general method for preparing Fischer-type alkoxycarbene complexes 1 is reported. This method involves the alkylation of acylate complexes 7 with alkyldiphenylsulfonium salts 10 with a variety of functionalized alkyl groups. The alkylation of tetramethylammonium pentacarbonyl (1-oxyalkylidene) chromate (0) 7a-c, tetramethylammonium pentacarbonyl (1-oxymethylidene) molybdate (0) 7d, and ...