A Graphical Adversarial Risk Analysis Model for Oil and Gas Drilling Cybersecurity

Oil and gas drilling is based, increasingly, on operational technology, whose cybersecurity is complicated by several challenges. We propose a graphical model for cybersecurity risk assessment based on Adversarial Risk Analysis to face those challenges. We also provide an example of the model in the context of an offshore drilling rig. The proposed model provides a more formal and comprehensive analysis of risks, still using the standard business language based on decisions, risks, and value.Comment: In Proceedings GraMSec 2014, arXiv:1404.163

POP-type ligands : Variable coordination and hemilabile behaviour

Hemilabile ligands – ligands containing two or more potential donors to a metal centre, of which one or more can dissociate – have the ability to provide a transition metal complex with open coordination sites at which reactivity can occur, or stabilise low coordinate intermediates along reaction pathways. POP-type ligands and in particular POP, Xantphos, DBFphos and DPEphos-based ligands contain three possible binding sites: two phosphines and an ether linker, thus have the potential to show κ1-, κ2- or κ3-binding modes. This review summarises the examples where POP-type ligands display hemilabile, or closely related variable coordination, characteristics in either synthesis or catalysis

Assessing and forecasting cybersecurity impacts

Cyberattacks constitute a major threat to most organizations. Beyond financial consequences, they may entail multiple impacts that need to be taken into account when making risk management decisions to allocate the required cybersecurity resources. Experts have traditionally focused on a technical perspective of the problem by considering impacts in relation with the confidentiality, integrity, and availability of information. We adopt a more comprehensive approach identifying a broader set of generic cybersecurity objectives, the corresponding set of attributes, and relevant forecasting and assessment models. These are used as basic ingredients for decision support in cybersecurity risk management.Peer reviewe

Origin of the Anti-Markovnikov Hydroamination of Alkenes Catalyzed by L-Au(I) Complexes : Coordination Mode Determines Regioselectivity

The reaction mechanism and regioselectivity for the gold(I)-catalyzed hydroamination reaction of terminal alkenes are analyzed by means of density functional theory (DFT) calculations. The influence of the nature of the olefin as well as the ligand present in the gold(I) catalyst on the regioselectivity is investigated. The anti-Markovnikov addition is preferred for some alkenes, particularly those having cyclopropyl or good electron-withdrawing groups in their structures. The regioselectivity of the process is quantitatively analyzed with the help of state-of-the-art computational methods, namely, the activation strain model (ASM) of reactivity and natural orbitals for chemical valence (NOCV) method. It is found that the back-bonding interactions in the initially formed π-complex are directly related to the Gibbs energy barrier difference between the Markonikov and anti-Markovnikov additions. It can be concluded that the coordination mode of the initial π-complex ultimately controls the regioselectivity outcome of the transformation

Hydroamination of C–C Multiple Bonds with Hydrazine Catalyzed by N‑Heterocyclic Carbene–Gold(I) Complexes: Substrate and Ligand Effects

In this work, we computationally address, from DFT calculations, mechanistic issues of the recently described hydroamination reactions catalyzed by (carbene) gold­(I) complexes that use hydrazine as N-nucleophile. We have explored the hydrohydrazination of alkynes, alkenes, and allenes using three gold–carbene catalysts reported by Bertrand’s and Hashmi’s groups. Aspects such as the associative or dissociative nature of the ligand exchange between hydrazine and the substrate, the generation of the catalytically active π-complex, the inner- or outer-sphere mechanism for the nucleophilic attack, the nitrogen to carbon proton transfer or the relative importance of the ligand substitution, the nucleophile addition, and the proton transfer barriers in the catalytic cycle are analyzed in light of the DFT results, taking into account the nature of the carbene ligand and the substrate. The study can provide background for the design of further hydroamination reactions using simple small N-nucleophiles

An adversarial risk analysis framework for cybersecurity

Risk analysis is an essential methodology for cybersecurity as it allows organizations to deal with cyber threats potentially affecting them, prioritize the defense of their assets, and decide what security controls should be implemented. Many risk analysis methods are present in cybersecurity models, compliance frameworks, and international standards. However, most of them employ risk matrices, which suffer shortcomings that may lead to suboptimal resource allocations. We propose a comprehensive framework for cybersecurity risk analysis, covering the presence of both intentional and nonintentional threats and the use of insurance as part of the security portfolio. A simplified case study illustrates the proposed framework, serving as template for more complex problems

Mechanistic insight into palladium-catalyzed cycloisomerization: a combined experimental and theoretical study

The cycloisomerization of enynes catalyzed by Pd(OAc)2 and bis-benzylidene ethylenediamine (bbeda) is a landmark methodology in transition-metal-catalyzed cycloisomerization. However, the mechanistic pathway by which this reaction proceeds has remained unclear for several decades. Here we describe mechanistic investigations into this reaction using enynamides, which deliver azacycles with high regio- and stereocontrol. Extensive (1)H NMR spectroscopic studies and isotope effects support a palladium(II) hydride-mediated pathway and reveal crucial roles of bbeda, water, and the precise nature of the Pd(OAc)2 pre-catalyst. Computational studies support these mechanistic findings and lead to a clear picture of the origins of the high stereocontrol that can be achieved in this transformation, as well as suggesting a novel mechanism by which hydrometalation proceeds

Mechanistic Insights on the Hydration of Terminal and Internal Allenes Catalyzed by [(NHC)Au]⁺

The reaction mechanism for the hydration of internal and terminal allenes catalyzed by [Au­(NHC)]⁺ is analyzed by means of DFT calculations. Several reaction pathways for generating the two possible regioisomers were evaluated. Direct addition on coordinated allenes or to an intermediate with a σ-allylic cation structure as suggested for the Au­(I)-catalyzed hydroamination of allenes were considered. The isomerization between both regioisomeric products catalyzed by the same Au­(I) catalyst was also investigated as suggested for hydroalkoxylation of allenes. The regioselectivity of the reaction predicted by computation agrees with experiment for both terminal and internal allenes. The presence of alkyl or aryl substituents introduces differences in the reaction mechanism for the hydration process