ChemInform Abstract: Steric and Electronic Effects on the Photochemical Reactivity of Oxime Acetates of β,γ-Unsaturated Aldehydes.

The selective hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols can reach high selectivity and activity at room temperature using Pt nanoparticles immobilized on a non-porous Al2O3 support stabilized by aspartic acid.

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Michael Additions of Benzotriazole-Stabilized Carbanions. A Review

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19980599 ◽

1998 ◽

Vol 63 (5) ◽

pp. 599-613 ◽

Cited By ~ 14

Author(s):

Alan R. Katritzky ◽

Ming Qi

Keyword(s):

Steric Hindrance ◽

Electronic Effect ◽

Steric Effects ◽

Unsaturated Ketone ◽

Electronic Effects ◽

Michael Additions ◽

Unsaturated Aldehydes ◽

Michael Acceptor ◽

Michael Acceptors ◽

Electron Withdrawing Group

The 1,4-addition of benzotriazole-stabilized carbanions to Michael acceptors is reviewed. The selectivity between 1,4- and 1,2-addition depends significantly on the electronic effect of the carbanion (usually lithium is the counterion), the type of the Michael acceptor, and steric effects. Steric hindrance of the benzotriazolyl group probably enhances the regioselectivity. Normally, 1,4-additions to α,β-unsaturated ketone or ester are observed for carbanions stabilized by a benzotriazolyl group and an electron-withdrawing group (e.g. aryl, vinyl, carbonyl). For α,β-unsaturated aldehydes as Michael acceptors, 1,2-addition is more likely, except where electronic effects are very strong. A review with 39 references.

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Geometric and electronic effects in the selective hydrogenation of $alpha;, $beta;-unsaturated aldehydes over zeolite-supported metals

Journal of Catalysis ◽

10.1016/0021-9517(91)90275-9 ◽

1991 ◽

Vol 131 (2) ◽

pp. 401-411 ◽

Cited By ~ 105

Author(s):

D BLACKMOND

Keyword(s):

Selective Hydrogenation ◽

Electronic Effects ◽

Unsaturated Aldehydes ◽

Alpha Beta ◽

Supported Metals

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On the Crystal Chemistry of Inorganic Nitrides: Crystal-Chemical Parameters and Opportunities in the Exploration of Their Compositional Space

10.26434/chemrxiv.11626974.v2 ◽

2020 ◽

Author(s):

Olivier Charles Gagné

Keyword(s):

Functional Properties ◽

A Priori ◽

Lone Pair ◽

Length Variation ◽

Electronic Effects ◽

Statistical Knowledge ◽

Redox Active ◽

Multiply Bonded ◽

Jahn Teller ◽

Compositional Space

The scarcity of nitrogen in Earth’s crust, combined with challenging synthesis, have made inorganic nitrides a relatively-unexplored class of compounds compared to their naturally-abundant oxide counterparts. To facilitate exploration of their compositional space via a priori modeling, and to help a posteriori structure verification not limited to inferring the oxidation state of redox-active cations, we derive a suite of bond-valence parameters and Lewis-acid strength values for 76 cations observed bonding to N3-, and further outline a baseline statistical knowledge of bond lengths for these compounds. We examine structural and electronic effects responsible for the functional properties and anomalous bonding behavior of inorganic nitrides, and identify promising venues for exploring uncharted compositional spaces beyond the reach of high-throughput computational methods. We find that many mechanisms of bond-length variation ubiquitous to oxide and oxysalt compounds (e.g., lone-pair stereoactivity, the Jahn-Teller and pseudo Jahn-Teller effects) are similarly pervasive in inorganic nitrides, and are occasionally observed to result in greater distortion magnitude than their oxide counterparts. We identify inorganic nitrides with multiply-bonded metal ions as a promising venue in heterogeneous catalysis, e.g. in the development of a post-Haber-Bosch process proceeding at milder reaction conditions, thus representing further opportunity in the thriving exploration of the functional properties of this emerging class of materials.

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