Regioselective removal of allylic nitro groups via hydride transfer

Ab Initio MO Study of the Geometry, η3 ⇄ η1 Conversion, and Reductive Elimination of a Palladium(II) η3-Allyl Hydride Complex and Its Platinum(II) Analogue

“…These results provide meaningful suggestions concerning the palladium-catalyzed reductive cleavage of allyl compounds, − as follows: (1) It is very difficult to detect PdH(η 3 -C 3 H 5 )(PR 3 ), and (2) an attempt to detect such an η 3 -allyl hydride complex should be made by using the Pt analogue since C−H reductive elimination is more difficult in PtH(η 3 -C 3 H 5 )(PR 3 ).…”

“…Transition metal η 3 -allyl complexes, as well as transition metal σ-alkyl complexes, play important roles as active species and/or key intermediates in many reactions catalyzed by transition metal complexes − In this regard, detailed knowledge such as geometries, bonding nature, and reactivities of transition metal η 3 -allyl complexes is indispensable to understanding catalytic properties of transition metal complexes. However, it is not easy in general to obtain the above-mentioned, detailed knowledge.…”

“…In this work, geometry, bonding, η 3 ⇄ η 1 interconversion (eq 2), and C−H reductive elimination of MH(η 3 -C 3 H 5 )(PH 3 ) (M = Pd, Pt; eq 3) are theoretically investigated, using ab initio MO/MP2-MP4, SD-CI, and coupled-cluster with double substitution (CCD) methods. We investigated eqs 2 and 3, because these are typical reactions of transition metal η 3 -allyl complexes − , and because detailed knowledge is not available on eq 3, which is important in palladium-catalyzed reductive cleavage of allyl compounds. − Our intention with this work is to present the first detailed study on the reductive elimination of eq 3 such as the transition-state (TS) structure, the activation energy ( E a ), the reaction energy (Δ E ), a comparison of reactivity between M = Pd and Pt, and a comparison of the C−H reductive elimination between MH(η 3 -C 3 H 5 )(PH 3 ) and a similar transition metal alkyl hydride complex, MH(CH 3 )(PH 3 ).…”

Theoretical Study of the Structure, Bonding Nature, and Reductive Elimination Reaction of Pd(XH3)(η3-C3H5)(PH3) (X = C, Si, Ge, Sn). Hypervalent Behavior of Group 14 Elements

“…Transition-metal η 3 -allyl complexes including hydride, alkyl, silyl, and similar group 14 elements play versatile roles as active species and/or key intermediates in many organic transformations . For instance, PdH( η 3 -C 3 H 5 )(PR 3 ) was postulated to serve as a key intermediate and to undergo C−H reductive elimination (eq 1) in Pd-catalyzed reductive cleavage of allyl compounds by formic acid. − The same C−H reductive elimination was reported in η 3 -allyl complexes of Ni and Pt. , The similar C−C reductive elimination of M(aryl)( η 3 -C 3 H 5 )(PR 3 ) n (M = Ni, Pd; n = 1, 2) was investigated in detail in Pd-catalyzed silylation of dienes , and allyl compounds .…”

A new approach to kainoids through tandem Michael reaction methodology: application to the enantioselective synthesis of (+)- and (-)-.alpha.-allokainic acid and to the formal synthesis of (-)-.alpha.-kainic acid

“…[2S-(2a,3/?,4a)]-4-Acetyl-l-[ (l,l- (l,l-dimethylethyl)dimethylsilyl]oxy]methyl]-3-pyrrolidineacetic Acid Ethyl Ester (22). Compound 21 (1.58 g, 3.64 mmol), (Boc)20 (2.73 g, 10.92 mmol) in MeOH (53 mL), and 10% Pd/C (0.27 g) were hydrogenated for 48 h at rt under 3 atm of H2 with a Parr shaker.…”