Mechanism of formation and breakdown of amine tetrahedral addition compounds of a phthalimidium cation. Relative leaving group abilities of amines and alkoxide ions

1974 ◽  
Vol 96 (2) ◽  
pp. 499-506 ◽  
Author(s):  
Norman Gravitz ◽  
William P. Jencks
Keyword(s):  
Mechanism Of Formation ◽  
Leaving Group

Preparation of 1-Adamantyl Ketones: Structure, Mechanism of Formation and Biological Activity of Potential By-Products

2006 ◽  
Vol 71 (5) ◽  
pp. 709-722 ◽  
Author(s):  
Robert Vícha ◽  
Marek Nečas ◽  
Milan Potáček
Keyword(s):  
Biological Activity ◽  
Grignard Reagents ◽  
Adamantane Derivatives ◽  
Mechanism Of Formation ◽  
Carbonyl Chloride ◽  
Leaving Group ◽  
Ar Process ◽  
By Products

Reactions between adamantane-1-carbonyl chloride and several Grignard reagents as well as interactions with solvents have been examined. Some new and unexpected adamantane derivatives were isolated, fully characterized and their biological activity determined. In particular, an unexpected isochromanone 16 was formed in an SEAr process, in which a stable hydrocarbon was the leaving group.

Regarding the mechanism of formation of nonmetallic inclusions conglomerates of system Al2O3-MgO

2019 ◽  
Vol 75 (12) ◽  
pp. 1341-1351
Author(s):  
A. A. Safronov ◽  
V. S. Dub ◽  
V. V. Orlov ◽  
K. L. Kosyrev ◽  
A. S. Loskutov ◽  
...  
Keyword(s):  
Nonmetallic Inclusions ◽  
Mechanism Of Formation

Assessment of ability to varnish turbine oils

2020 ◽  
Vol 06 ◽  
pp. 28-33
Author(s):  
I.V. Mitin ◽  
◽  
I.R. Tatur ◽  
K.U. Smirnov ◽  
A.M. Suloev ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
Mechanism Of Formation ◽  
Critical Situation ◽  
Antioxidant Content ◽  
Turbine Equipment

The reasons for the formation of varnish deposits of turbine oils are determined. It is shown that the performance of turbine oils is determined by methods of ASTM D7843 (MPC) and ASTM D6971 (RUL) can be assessed, the process of formation of varnish deposits, the level of antioxidant properties, antioxidant content of, amend, and extend the oil change, and to predict critical situation in the operation of turbine equipment. The mechanism of formation of varnish deposits in turbine oils is proposed.

General Cyclopropane Assembly via Enantioselective Redox-Active Carbene Transfer to Aliphatic Olefins

2018 ◽  
Author(s):  
Marc Montesinos-Magraner ◽  
Matteo Costantini ◽  
Rodrigo Ramirez-Contreras ◽  
Michael E. Muratore ◽  
Magnus J. Johansson ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Asymmetric Synthesis ◽  
Chemical Space ◽  
Synthetic Approach ◽  
Asymmetric Cyclopropanation ◽  
Redox Active ◽  
Wide Range ◽  
Leaving Group ◽  
Stereoelectronic Properties ◽  
Carbene Transfer

Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates and reagents, even when targeting similar compounds. This limits the speed and chemical space available for discovery campaigns. Here we introduce a practical and versatile diazocompound, and we demonstrate its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. We found that the redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect enabled the asymmetric cyclopropanation of a wide range of olefins including unactivated aliphatic alkenes, enabling the 3-step total synthesis of (–)-dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally-differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons<i>.</i>

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