The X‐ray Crystal Structure of a Cuprate–Carbonyl π‐Complex

Abstract

Why is it π? The first X‐ray crystal structure of a cuprate–carbonyl π‐complex has been obtained for the intermediate prepared from Me2CuLi and fluorenone (see scheme). It is also the first structure of a π‐complex between an organocuprate and a double bond of any kind.

Periodic Trends in the Binding of a Phosphine‐Tethered Ketone Ligand to Fe, Co, Ni, and Cu

“…The product was extracted with THF,a nd the organic phases were dried in vacuum to give product 3 as ag reen solid (103 mg, 0.152 mmol, 83 %). ( Ph dpbp)FeCl (5):N aphthalene (141.2 mg, 1.1 mmol) was dissolved in THF (20 mL) in the glovebox at RT.Alump of Na 0 was added and the mixture was stirred for 3h to give ad ark green solution. FeCl 2 (115.3 mg, 0.909 mmol) was suspended in THF (8 mL) in a vial, and Ph dpbp (500.2 mg, 0.908 mmol) was dissolved in another vial in THF (12 mL).…”

“…The p complexes of carbon-carbon and carbon-heteroatom multiple bonds are reactive intermediates in al argen umber of catalytic reactions, which includesh ydrogenations, hydrofunctionalizations, oligo-and polymerizations. The latter,l ess common binding mode has been proposed in intermediate structures for the Cu-catalyzed addition of Grignardr eagents, [5,6] Ru-catalyzed hydrogenation reactions, [7,8] and oxidative additiono fa rylketone CÀCb onds. [4] The polarity of the carbon-oxygen double bonds in aldehydes and ketones sets them apart amongst p-binding ligands.…”

“…The C=Ob ond can bind to transition metalst hroughe ither an h 1 (O)-interaction based on s-donation,w hich is allowed by the presence of oxygen-centered lone-pairs, or through a p-coordinating h 2 (C,O) interaction. The latter,l ess common binding mode has been proposed in intermediate structures for the Cu-catalyzed addition of Grignardr eagents, [5,6] Ru-catalyzed hydrogenation reactions, [7,8] and oxidative additiono fa rylketone CÀCb onds. [9][10][11] In particular, Piers and co-workers recently re-portedaremarkable oxygen atom transfer from N 2 Ot oa nI r =C double bond to yield an iridaepoxide complex that serves as an intermediate in the formalh ydrogenation of N 2 Ot oN 2 and H 2 O.…”

“…To p: X-ray crystal structure of ( Ph dpbp)FeCl(5). Co-crystallized toluene molecule and hydrogen atoms are omitted for clarity;ellipsoids are showna t50 %p robability level.…”

Catalytic Asymmetric Alkylation of Acylsilanes

“…[8a] Lewis acids are expected to prevent the coordination of the magnesium to the carbonyl moiety, thereby allowing the catalytic pathway to outcompete reduction. [11] A survey of Lewis acids (entries [9][10][11][12][13], demonstrated that in the presence of CeCl 3 , both the selectivity and the enantioselectivity improved (compare entries 1 and 9). The best selectivity (2 a/3 a = 3:1) was obtained when BF 3 ·Et 2 O was used as an additive, but at the cost of a drop in e.r.…”