A new example of structurally characterized conjugated bis-guanidinate (CBG) supported zinc (I) dimer, i.e., LZnZnL (3) (L = {(ArNH)(ArN)–C=N–C=(NAr)(NHAr)}; Ar = 2,6-Et2-C6H3)) with a Zn-Zn bond is reported. Moreover, homoleptic...

The conjugated bis-guanidinate (CBG)-stabilized zinc hydride, [{LZnH} 2 ; (L = {(ArNH)(ArN)−C�N− C�(NAr)(NHAr)}; Ar = 2,6-Et 2 -C 6 H 3 )] (Zn-1), is shown to be a highly active catalyst for the double reduction of isonitriles and nitriles with pinacolborane (HBpin) in this study. A wide array of isonitriles and nitriles, including aryl and alkyl groups, underwent hydroboration to afford exclusively 1,2-and 1,1-diborylated amine products, respectively. A series of stoichiometric reactions were performed to understand the reaction mechanisms. Hydroboration of isonitrile proceeds through the formation of zinc formimidoyl complex, [LZnC(H)N( t Bu)] 2 (Zn-2), while nitrile hydroboration through zinc vinylidenamido complex, [LZnNC(H)(C 6 H 5 )] 2 (Zn-3). Moreover, compounds Zn-2 and Zn-3 are isolated and thoroughly characterized. Such molecular zinc complexes are rare in the literature.

Guanidines are important organic components in terms of their multidimensional application, such as crucial synthons in organic chemistry, potential Lewis basic nature, and finally, acts as a versatile ligand in the field of coordination chemistry. Its variational coordination modes with different metals across the periodic table are well summarized in the literature. Though the transition elements take the lead in the guanidinate metal chemistry, there are some reports on the main group metal guanidinate complexes. This piece of work summarizes a detailed study of the recent advances in the coordination chemistry of guanidinate alkaline earth metal complexes and their catalytic applications.