Insertion Chemistry of Lutetacyclopropene toward Unsaturated C−O/C−N Bonds

• Published in: Chemistry : a European journal 2021-11, Vol.27 (66), p.16498-16504
• Main Authors: Lv, Ze‐Jie, Liu, Wei, Zhu, Miaomiao, Chai, Zhengqi, Wei, Junnian, Zhang, Wen‐Xiong
• Format: Article
• Language: English
• Subjects: insertion; metallacycles; metallacyclopropenes; rare-earth metals; reductive coupling
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202103065

Although the reaction chemistry of transition metallacyclopropenes has been well‐established in the last decades, the reactivity of rare‐earth metallacyclopropenes remains elusive. Herein, we report the reaction of lutetacyclopropene 1 toward a series of unsaturated molecules. The reaction of 1 with one equiv. of PhCOMe, Ar1CHO (Ar1=2,6‐Me2C6H3), W(CO)6, and PhCH=NPh provided oxalutetacyclopentenes, metallacyclic lutetoxycarbene, and azalutetacyclopentene via 1,2‐insertion of C=O, C≡O, or C=N bonds into Lu−Csp2 bond, respectively. However, the reaction between 1 and Ar2N=C=NAr2 (Ar2=4‐MeC6H4) gave an acyclic lutetium complex with a diamidinate ligand by the coupling of one molecule of 1 with two carbodiimides, irrespective of the amount of carbodiimide employed. More interestingly, when 1 was treated with two equiv. of Ar1CHO, the reductive coupling of two C=O bonds was discovered to give a lutetium pinacolate complex along with the release of tolan. Remarkably, the reactivity of 1 is significantly different from that of scandacyclopropenes; these metallacycles derived from 1 all represent the first cases in rare‐earth organometallic chemistry. The diversified and unique reactivity of lutetacyclopropene toward ketone, aldehyde, tungsten hexacarbonyl, imine, and carbodiimide was demonstrated to give a series of novel lutetacycles, including oxalutetacyclopentenes, metallacyclic lutetoxycarbene, azalutetacyclopentene, lutetium pinacolate, as well as an acyclic complex with a diamidinate ligand. The intrinsic reactivity of lutetacyclopropene was probably caused by the strongly nucleophilic and high polarized nature of Lu−Csp2 bonds.