2008
Substituent Effect on exo Stereoselectivity in the 1,3-Dipolar Cycloaddition Reaction of Tulipalin A with Nitrile Ylides
MELŠA, Petr; Michal ČAJAN; Zdeněk HAVLAS a Ctibor MAZALZákladní údaje
Originální název
Substituent Effect on exo Stereoselectivity in the 1,3-Dipolar Cycloaddition Reaction of Tulipalin A with Nitrile Ylides
Název česky
Substituent Effect on exo Stereoselectivity in the 1,3-Dipolar Cycloaddition Reaction of Tulipalin A with Nitrile Ylides
Autoři
Vydání
Journal of Organic Chemistry, 2008, 0022-3263
Další údaje
Jazyk
angličtina
Typ výsledku
Článek v odborném periodiku
Obor
10401 Organic chemistry
Stát vydavatele
Spojené státy
Utajení
není předmětem státního či obchodního tajemství
Impakt faktor
Impact factor: 3.952
Označené pro přenos do RIV
Ano
Kód RIV
RIV/00216224:14310/08:00033644
Organizační jednotka
Přírodovědecká fakulta
UT WoS
Klíčová slova česky
CH-pi interakce; substituční efekt; stereoselektivita; cykloadice
Klíčová slova anglicky
CH-pi Interaction; Substituent effect; stereoselectivity; cycloaddition
Příznaky
Mezinárodní význam, Recenzováno
Změněno: 24. 3. 2010 16:47, doc. RNDr. Ctibor Mazal, CSc.
V originále
1,3-Dipolar cycloaddition reactions of dihydro-3-methylene-2(3H)-furanone (Tulipalin A) with various benzonitrile(p-X-benzylide) ylides prefer formation of exo-cycloadducts in the extent of corresponding to an increasing electron donor character of the substituent X in p-position of benzylide phenyl ring of 1,3-dipolar reagent. The substituent effect on diastereoselectivity of the 1,3-DC reaction is rationalized in terms of CH/p interaction between dipole and dipolarophile in an exo-transition state. The interaction is demonstrated by the correlation of the observed diastereoselectivities with substituent Hammett sigma constants, which shows a small negative r value. A certain contribution of CO/p interaction between lactone carbonyl and the substituted phenyl ring to mediation of the substituent effect is also discussed. The energy profiles of both reaction pathways were analyzed using DFT and RI-MP2 theoretical approaches. Calculated energy and structural differences between located transition states are consistent with reaction diastereoselectivities.
Česky
1,3-Dipolar cycloaddition reactions of dihydro-3-methylene-2(3H)-furanone (Tulipalin A) with various benzonitrile(p-X-benzylide) ylides prefer formation of exo-cycloadducts in the extent of corresponding to an increasing electron donor character of the substituent X in p-position of benzylide phenyl ring of 1,3-dipolar reagent. The substituent effect on diastereoselectivity of the 1,3-DC reaction is rationalized in terms of CH/p interaction between dipole and dipolarophile in an exo-transition state. The interaction is demonstrated by the correlation of the observed diastereoselectivities with substituent Hammett sigma constants, which shows a small negative r value. A certain contribution of CO/p interaction between lactone carbonyl and the substituted phenyl ring to mediation of the substituent effect is also discussed. The energy profiles of both reaction pathways were analyzed using DFT and RI-MP2 theoretical approaches. Calculated energy and structural differences between located transition states are consistent with reaction diastereoselectivities.
Návaznosti
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