Reactivity and Selectivity of Ortho-Metalated Rhodium(II) Complexes in C−H Insertion Reactions of α-Diazo Compounds

• Published in: Organometallics Vol. 17; no. 16; pp. 3442 - 3447
• Main Authors: Estevan, Francisco, Lahuerta, Pascual, Pérez-Prieto, Julia, Pereira, Inés, Stiriba, Salah-Eddine
• Format: Journal Article
• Language: English
• Published: American Chemical Society 03-08-1998
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om971070q

Regioselective intramolecular C−H insertion reactions of α-diazo β-keto esters and α-diazo ketones are mediated by Rh2[OOCR]4 - x [PC] x (x = 1, 2; PC = ortho-metalated phosphine; R = CH3, C3F7). In particular, the intramolecular transformation of 1-diazo-5-methyl-3-propyl-2-hexanone catalyzed by Rh2[OOCCH3]2[PC]2 (PC = (C6H4)P(C6H5)2, head-to-tail (H−T) configuration) afforded only the tertiary C−H insertion product. By comparison, no C−H insertion reaction was promoted by doubly metalated complexes with a head-to-head (H−H) configuration. Rh2[OOCR]3[PC] compounds were found to be less suited for these type of reactions.