Steric hindrance in potassium atom-oriented molecule reactions. Methyl iodide and tert-butyl iodide

1975 ◽  
Vol 97 (7) ◽  
pp. 1710-1715 ◽  
Author(s):  
George Marcelin ◽  
Philip R. Brooks
Keyword(s):  
Methyl Iodide ◽  
Steric Hindrance ◽  
Potassium Atom ◽  
Tert Butyl ◽  
Oriented Molecule

Tri(tert-butyl)phosphinoxid, -imin, -methylen und -boran / Tri(tert-butyl)phosphine Oxide, Imine, Methylene and Borane

1978 ◽  
Vol 33 (12) ◽  
pp. 1556-1558 ◽  
Author(s):  
Hubert Schmidbaur ◽  
Günter Blaschke
Keyword(s):  
Thermal Decomposition ◽  
Phosphine Oxide ◽  
Steric Hindrance ◽  
Reductive Elimination ◽  
Tert Butyl

Abstract Tri(tert-butyl)phosphine Oxide, Imine, Methylene, Borane Tri(tert-butyl)phosphine oxide, imine, methylene and borane have been prepared and their properties investigated. The imine is chemically inert due to strong steric hindrance. Its thermal decomposition at 200 °C leads to tri(tert-butyl)-pliosphine, in contrast to the methylene analogue which undergoes reductive elimination of isobutene. Both the oxide and borane are thermally very stable (> 250 °C).

2,6-Di-tert-butyl-4-(phenyliminomethyl)phenol

2006 ◽  
Vol 62 (4) ◽  
pp. o1455-o1456
Author(s):  
Xi-Long Yan ◽  
Li-Gong Chen ◽  
Tao Zeng
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bond ◽  
Benzene Ring ◽  
Dihedral Angle ◽  
Hydroxy Group ◽  
Steric Hindrance ◽  
Phenyl Ring ◽  
Tert Butyl

In the title molecular structure, C21H27NO, the dihedral angle between the phenyl ring and the benzene ring planes is 63.28 (9) Å. It appears that the hydroxy group is prevented from forming a hydrogen bond because of steric hindrance by the tert-butyl groups.

Stereochemistry of the Bucherer–Bergs and Strecker Reactions of 4-tert-Butylcyclohexanone

1975 ◽  
Vol 53 (22) ◽  
pp. 3339-3350 ◽  
Author(s):  
John T. Edward ◽  
Chote Jitrangsri
Keyword(s):  
Nitrogen Atom ◽  
Carbon Disulfide ◽  
Steric Hindrance ◽  
Detailed Consideration ◽  
Tert Butyl ◽  
Strecker Reaction ◽  
Butyl Group ◽  
Tert Butyl Group

The spirohydantoin (α-isomer) obtained from 4-tert-butylcyclohexanone by the Bucherer–Bergs reaction has been shown by n.m.r., u.v., and considerations of steric hindrance to have the tert-butyl group and 1′-nitrogen atom cis; the β isomer obtained via the Strecker reaction, or via modified Bucherer–Bergs reactions employing carbon disulfide or carbon oxysulfide, has these groups trans. The differing stereochemical courses of the various reactions can be explained by a detailed consideration of their mechanisms.

Reaction of Xenon Difluoride. Part II. Oxidative-fluorination of Phosphorus and Iodine Compounds and Cleavage of Silicon–Sulfur and Silicon–Nitrogen Bonds

1975 ◽  
Vol 53 (20) ◽  
pp. 3044-3052 ◽  
Author(s):  
James Andrew Gibson ◽  
Ronald Kirk Marat ◽  
Alexander F. Janzen
Keyword(s):  
Methyl Iodide ◽  
Xenon Difluoride ◽  
Alkyl Aryl ◽  
Tert Butyl ◽  
Butyl Group ◽  
Tert Butyl Group ◽  
Iodine Compounds ◽  
Stable Xenon ◽  
Nitrogen Bonds ◽  
Nitrogen Bond

Reaction of alkyl(aryl)phosphines with xenon difluoride gives alkyl(aryl)hydridofluorophosphoranes which were characterized by proton and fluorine n.m.r. spectroscopy. With phenylchlorophosphines, substitution of chlorine by fluorine accompanied oxidative-fluorination to give phenylfluorophosphoranes, (C6H5)nPF5−n. With tert-butylchlorophosphines, chlorination of the tert-butyl group accompanied oxidative-fluorination, and a mixture of products was obtained. Reaction of xenon difluoride with methyl iodide gives methyliodine(III) difluoride, characterized by proton and fluorine n.m.r. spectroscopy.Silicon–sulfur and silicon-nitrogen bonds are cleaved by xenon difluoride and an intermediate containing a xenon–nitrogen bond is postulated.Reaction of xenon difluoride with hexafluoroacetone, perfluoropinacol, or disodium perfluoropinacolate failed to give stable xenon esters.

Enthalpies of transfer of aliphatic compounds from vapor to solvents. Steric hindrance to functional group solvation

1976 ◽  
Vol 54 (24) ◽  
pp. 3857-3859 ◽  
Author(s):  
Richard Fuchs ◽  
Preetpal S. Saluja
Keyword(s):  
Steric Hindrance ◽  
Functional Group ◽  
Dipole Interaction ◽  
Ethylenic Bond ◽  
Aliphatic Compounds ◽  
Enthalpies Of Transfer ◽  
Tert Butyl ◽  
Induced Dipole ◽  
Butyl Ketone

Enthalpies of transfer from the vapor to solution (ΔH(v → S)) in cyclohexane are similar for alkenes and the corresponding alkanes. The transfer from vapor to dimethylformamide is about 0.6 kcal/mol more exothermic for 1-alkenes, which results from the dipole-induced dipole interaction of the solvent dipole with the π system. When the ethylenic bond is hindered by large adjacent groups (trans-1,2-di-tert-butylethylene) to the approach of solvent dipoles, ΔH(v → DMF) becomes similar to that of the corresponding alkane (1,2-di-tert-butylethane). Similarly the interaction of di-tert-butyl ketone with DMF is 0.7 kcal/mol weaker than that of the less hindered isomer, 2-nonanone.

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