The synthesis of 3-(trimethylsilyl)benzo [b]biphenylene-2-yl triflate (2) was achieved through the two alternative routes depicted in Scheme 2, both based in the construction of the 2,3-disubstituted benzo [b]biphenylene core by means of a cobalt(I)catalyzed [2+2+2] cycloaddition of 2,3-diethynylnaphthalene (3) with an appropriate alkyne. Thus, reaction of 3 with bis(trimethylsilyl)acetylene (BTMSA, used as co-solvent) in the presence of CpCo(CO)2, under heating and irradiation, provided 2,3-bis(trimethylsilyl)benzo [b]biphenylene (4) in a satisfactory 90% yield. For the transformation of 4 into triflate 2, first we attempted the protocol previously developed for the synthesis of an analogous biphenylyne precursor, which allowed the isolation of 2 in low yields and with scarce reproducibility. Better results were obtained when 4 was subjected to a double bromodesilylation followed by nucleophilic substitution of one of the bromine atoms by methoxide to yield 5. Subsequent treatment with BBr3 afforded an unstable o-bromophenol, which was directly subjected to the protocol developed in our group for the synthesis of o-(trimethylsilyl)aryl triflates to give 2 (route A in Scheme 2; six steps and 20.7% yield from 3). Alternatively, the Co(I)-catalyzed [2+2+2] cycloaddition of 3 with the trimethylsilyl alkynylboronate 6 afforded 7 in 40% yield. The ipso-hydroxylation of the arylboronic ester with sodium perborate, followed by triflation of the resulting phenol, allowed the straightforward synthesis of 2 in 68% yield (route B in Scheme 2; three steps and 27.2% overall yield from 3).