Titanium Tetrachloride Mediated Addition of 1,8-Bis(trimethylsilyl)-2,6-octadiene to Aldehydes. A One-Step Control of Four Stereogenic Carbon Centers

1994 ◽  
Vol 59 (7) ◽  
pp. 1709-1713 ◽  
Author(s):  
Helene Pellissier ◽  
Loiec Toupet ◽  
Maurice Santelli
Keyword(s):  
Titanium Tetrachloride ◽  
Carbon Centers ◽  
One Step ◽  
Step Control

scholarly journals Parallel One-Step Control of Parametrised Boolean Networks

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 560 ◽  
Author(s):  
Luboš Brim ◽  
Samuel Pastva ◽  
David Šafránek ◽  
Eva Šmijáková
Keyword(s):  
Control Problem ◽  
Boolean Networks ◽  
Actual State ◽  
Worst Case ◽  
Symbolic Data ◽  
One Step ◽  
The One ◽  
Step Control ◽  
Symbolic Algorithm ◽  
Naive Approach

Boolean network (BN) is a simple model widely used to study complex dynamic behaviour of biological systems. Nonetheless, it might be difficult to gather enough data to precisely capture the behavior of a biological system into a set of Boolean functions. These issues can be dealt with to some extent using parametrised Boolean networks (ParBNs), as this model allows leaving some update functions unspecified. In our work, we attack the control problem for ParBNs with asynchronous semantics. While there is an extensive work on controlling BNs without parameters, the problem of control for ParBNs has not been in fact addressed yet. The goal of control is to ensure the stabilisation of a system in a given state using as few interventions as possible. There are many ways to control BN dynamics. Here, we consider the one-step approach in which the system is instantaneously perturbed out of its actual state. A naïve approach to handle control of ParBNs is using parameter scan and solve the control problem for each parameter valuation separately using known techniques for non-parametrised BNs. This approach is however highly inefficient as the parameter space of ParBNs grows doubly exponentially in the worst case. We propose a novel semi-symbolic algorithm for the one-step control problem of ParBNs, that builds on symbolic data structures to avoid scanning individual parameters. We evaluate the performance of our approach on real biological models.

Numerical Integration of Some Stiff Constitutive Models of Inelastic Deformation

1980 ◽  
Vol 102 (1) ◽  
pp. 92-96 ◽  
Author(s):  
Virendra Kumar ◽  
Mahesh Morjaria ◽  
Subrata Mukherjee
Keyword(s):  
Numerical Integration ◽  
Inelastic Deformation ◽  
Time Integration ◽  
Constitutive Models ◽  
Integration Scheme ◽  
Uniaxial Deformation ◽  
Time Step ◽  
One Step ◽  
Numerical Time Integration ◽  
Step Control

Several strategies for numerical time-integration of some stiff constitutive models of inelastic deformation are presented in this paper. Numerical results and comparisons are presented for the integration of one such model for the case of uniaxial deformation under various prescribed histories of stress or strain. A simple one step Euler type integration scheme with automatic time-step control, which can be easily adapted to the solution of multiaxial boundary value problems, appears promising.

Perturbation analysis of GPC with one-step control horizon

Automatica ◽  
1991 ◽  
Vol 27 (4) ◽  
pp. 725-728 ◽  
Author(s):  
Abdel-Latif Elshafei ◽  
Guy Dumont ◽  
Ashraf Elnaggar
Keyword(s):  
Perturbation Analysis ◽  
One Step ◽  
Step Control

scholarly journals One-Step Regioselective Synthesis of Benzofurans from Phenols and α-Haloketones

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2187 ◽  
Author(s):  
Bingqiao Wang ◽  
Qiu Zhang ◽  
Juan Luo ◽  
Zongjie Gan ◽  
Wengao Jiang ◽  
...  
Keyword(s):  
Titanium Tetrachloride ◽  
Direct Synthesis ◽  
Regioselective Synthesis ◽  
Simple Protocol ◽  
One Step

Reported here is the direct synthesis of naphthofurans and benzofurans from readily available phenols and α-haloketones promoted by titanium tetrachloride which combines Friedel–Crafts-like alkylation and intramolecular cyclodehydration into one step. This simple protocol allows for the formation of a variety of high value naphthofurans and benzofurans within which a series of cyclic and acyclic groups are readily incorporated. This process demonstrates the advantages of high levels of regioselectivity, broad substrate scope, and moderate to excellent yields.

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