Page 1211 - Advanced Organic Chemistry Part A - Structure and Mechanisms, 5th ed (2007) - Carey _ Sundberg

1198 tetrahedral intermediate (cont.) triphenylmethyl radical, 967
in ester aminolysis, 660–661 triplet state, 1073, 1076–1077
Index in imine formation and hydrolysis, 646–650 tropylium ion, see cycloheptatrienyl cation
in reactions of carbonyl compounds,
325–331, 630
valence, 2
tetrahydropyrans
valence bond theory, 3
anomeric effect in, 228–232
valence shell electron pair repulsion, 7
radical conformation, 984
valence tautomerism, definition, 905
tetramethylethylenediamine (TMEDA)
van der Waals radii, 24–26
affect on organolithium compounds, 589–590
definition within DFT, 97
in reactions with esters, 678
table of, 26
thermodynamic control of product composition,
van der Waals strain
285–287
in cyclohexane derivatives, 154
in aldol addition, 690
in relation to butane conformation, 143–144
thermodynamic stability, 253–270
in relation to rotational barriers, 78–80
thexylborane
vicarious nucleophilic aromatic substitution,
formation of, 188
820–821
hydroboration by, 524
vinyl amines, see enamines, ethenamine
thiiranium ions
vinyl cations, 301, 435–436
as intermediates in sulfenylation of alkenes, 498
vinylcyclopropane
thiophene
thermal rearrangement of, 929
aromatic stabilization of, 758–759
vinyl ethers
electrophilic aromatic substitution of, 793–794
cycloaddition with diazomethane, 880–882
three electron bond
hydrolysis of, 485
in radicals, 313, 315, 316, 318
resonance in, 21–22
tin tetrachloride
vinyl radicals
as Lewis acid catalyst, 354–355
structure of, 985–986
titanium tetrachloride
substituent effects on, 985–986
as Lewis acid catalyst, 354–355, 849
VSEPR, see valence shell electron pair repulsion
in enantioselective Diels-Alder reactions,
865–866
water
TMEDA, see tetramethylethylenediamine
effect on mechanism of imine formation,
torsional barrier, see rotational barrier
648–650
torsional effects
Laplacian of electron density, 92
in enolate alkylation, 617
as solvent for Diels-Alder reaction, 850
torsional strain, see strain, torsional
Wilkinson’s catalyst, 174
transition state, definition, 253
Winstein-Grunwald equation, 412
transition state theory, 270–272
Wittig rearrangement, 943–944
transition structure
Woodward-Hoffmann rules
computational characterization of, 279–80
for concerted cycloaddition, 836–837
definition, 270
for electrocyclic reactions, 900
triafulvene, 754–757
2 6
tricyclo[3.1.0.0 ]hex-3-ene, from photolysis of in relation to photochemical reactions, 1099
for sigmatropic rearrangements, 912
benzene, 1134
1,3,5-trienes
electrocyclic reactions of, 893–894 X-ray crystal structures
heteroatom analogs of, electrocyclization, (+) and (-) forms of
910–911 2,5-diazabicyclo[2.2.2]octane-3,6-6-dione,
photochemical reactions, 1106–1107 1123–1124
triflate, see trifluoromethanesulfonate 1,6-methanocyclodeca-1,3,5,7,9-pentaene-3-
2,2,2-trifluoro-1-(9-anthryl)ethanol carboxylic acid,
as chiral additive for NMR spectra, 210 773–780
trifluoroacetic acid, addition to alkenes, 484–485 1,6-methanocyclodeca-1,3,5,7,9-pentaene, 730
trifluoroethanol, as solvent, 368, 412 2-methylpropenal-BF 3 complex, 849
trifluoromethanesulfonic acid, addition to 3,3-dimethyl-4-(t-butyldimethylsilyl)-2-
alkenes, 484 pentanone enolate,
trifluoromethylsulfonate, as leaving group, 613
413–414 benzoyl chloride-SbCl 5 complex, 810
triphenylmethyl cation, 426–427 benzoyl chloride-TiCl 4 dimeric complex, 810