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 MAZAL. Substituent Effect on exo Stereoselectivity in the 1,3-Dipolar Cycloaddition Reaction of Tulipalin A with Nitrile Ylides. Journal of Organic Chemistry. 2008, roč. 73, č. 8, s. 3032-3039. ISSN 0022-3263.

Základní 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: MELŠA, Petr (203 Česká republika), Michal ČAJAN (203 Česká republika), Zdeněk HAVLAS (203 Česká republika) a Ctibor MAZAL (203 Česká republika, garant).
• Vydání: Journal of Organic Chemistry, 2008, 0022-3263.

Další údaje

• Originální 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
• Kód RIV: RIV/00216224:14310/08:00033644
• Organizační jednotka: Přírodovědecká fakulta
• UT WoS: 000254883700007
• Klíčová slova česky: CH-pi interakce; substituční efekt; stereoselektivita; cykloadice
• Klíčová slova anglicky: CH-pi Interaction; Substituent effect; stereoselectivity; cycloaddition
• Štítky: cycloaddition, stereoselectivity, Substituent effect
• Příznaky: Mezinárodní význam, Recenzováno

Anotace

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.

Anotace 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

• MSM6198959218, záměr: Název: Komplexní sloučeniny a oxidy přechodných kovů s využitím v bioaplikacích a nanotechnologiích