A β-Carbon elimination strategy for convenient in situ access to cyclopentadienyl metal complexes

Abstract

Stable pre-ligands and common metal salts provide, via β-carbon elimination, access to Cp-metal complexes suitable for in situ catalyst preparation.

Synthesis of Functionalized (η5‐Indenyl)rhodium(III) Complexes and Their Application to C−H Bond Functionalization

“…Rovis reported that the use of a η 5 ‐heptamethylindenyl‐rhodium(III) [Ind*Rh III ] complex, which is synthesized by anion exchange (Scheme , middle and bottom), improves diastereoselectivity of the [4+2] annulation of benzamides with 3,3‐disubstituted cyclopropenes . Cramer reported the synthesis of unsubstituted indenyl‐ and 1,2,3‐trimethylindenyl–rhodium(III) complexes by β‐carbon elimination (Scheme , bottom), but their catalytic activity toward the C−H bond functionalization was not demonstrated . Thus, structural diversity of IndRh III complexes is very limited, especially, an electronically tuned one has not been reported to date.…”

“…[5] In the CÀHb ond functionalization, only as ingle example of the indenyl-rhodium(III) complex-catalyzed reaction has been reported. [8] Thus, structural diversity of IndRh III complexes is very limited,e specially,a ne lectronically tuned one has not been reported to date. [6,7] Cramer reported the synthesis of unsubstituted indenyl-and 1,2,3-trimethylindenyl-rhodium(III) com-plexes by b-carbone limination (Scheme 1, bottom), but their catalytic activity toward the CÀHb ond functionalization was not demonstrated.…”

“…[6,7] Cramer reported the synthesis of unsubstituted indenyl-and 1,2,3-trimethylindenyl-rhodium(III) com-plexes by b-carbone limination (Scheme 1, bottom), but their catalytic activity toward the CÀHb ond functionalization was not demonstrated. [8] Thus, structural diversity of IndRh III complexes is very limited,e specially,a ne lectronically tuned one has not been reported to date.…”

Rhenium‐Promoted C−C Bond‐Cleavage Reactions of Internal Propargyl Alcohols

“…In fact, reported examples of β‐carbon elimination reactions of alkoxides to give well‐defined metal complexes are still rare. To the best of our knowledge, there are only a few reports on isolation of metal complexes derived from β‐carbon elimination of tertiary alkoxide complexes, [8b, 14] only one report on isolation of metal complexes derived from β‐carbon elimination of secondary alkoxide complexes (i.e., the reactions of C 5 Me 5 C(OH)H(R) (R=Ph, n ‐pentyl and CO 2 Et) with [Rh(COD)(OH)] 2 to give ( η 5 ‐C 5 Me 5 )Rh(COD)), and no reports on isolation of metal complexes derived from β‐carbon elimination of primary alkoxide complexes.…”

Mild complexation protocol for chiral CpxRh and Ir complexes suitable for in situ catalysis

“…The released hydrochloric acid during the complexation is incompatible with some sensitive functional groups of designer Cp scaffolds. We have developed a complementary complexation strategy capitalizing on β-carbon elimination of cyclopentadienyl carbinols as Cp-ligand precursors 9. While this method consists of an improvement, it requires the synthesis of the ligand precursor by an additional synthetic step.…”