The electronically unsaturated compounds Re-2(CO)(8)[mu-Au(NHC)](mu-Ph), 1, and Re-2(CO)(8)[mu-Au-(NHC)](2), 2, were obtained from the reaction of Re-2(CO)(8)[mu-eta(2)-C(H)-C(H)Bu-n](mu-H) with MeAu(NHC), NHC = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene. Compound 1 was converted to the new compound Re-2(CO)(8)[mu-Au(NHC)](mu-H), 3, by reaction with H2. Addition of CO to 3 yielded the new compound Re-2(CO)(9)[Au(NHC)](mu-H), 4, which contains a terminally coordinated Au(NHC) group on one of the rhenium atoms, and the hydrido ligand was shifted to bridge the Re-Au bond. The mechanism of the formation of 4 was established by DFT computational analyses. Compound 3 also reacted with C2H2 by an addition with insertion into the Re-H bonds to yield the compound Re-2(CO)(8)[mu-Au(NHC)](mu-C2H3), 5, which contains a sigma-pi coordinated, bridging C2H3 ligand. The stereochemistry of the insertion was found to proceed preferentially with a cis- (syn-) stereochemistry. Compound 1 reacted with HCl to yield Re-2(CO)(8)[mu-Ph](mu-H), 6, and ClAu(NHC) by selective removal of the bridging Au(NHC) group. All new compounds were characterized by single-crystal X-ray diffraction analyses.