Ab initio and semiempirical modelling of stereoselectivities of Diels-Alder cycloadditions of furan and cyclopentadiene with norbornenes

Margetić, Davor; Warrener, Ronald N. (2003) Ab initio and semiempirical modelling of stereoselectivities of Diels-Alder cycloadditions of furan and cyclopentadiene with norbornenes. Croatica Chemica Acta, 76 (4). pp. 357-363. ISSN 0011-1643

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Abstract

Ab initio (RHF/3-21G and RHF/6-31G* basis sets) and semiempirical (AM1 and PM3) quantum chemical calculations have been applied to a study of Diels-Alder reactions of furan and cyclopentadiene as 1,3-dienes, with norbornene and 7-oxanorbornene as dienophiles, in order to model pi-facial selectivities and stereoselectivities of these reactions. To achieve this goal, transition states for these reactions are located and activation energies estimated. The exclusive exo pi-facial selectivity exhibited in these cycloadditions are readily predicted using semiempirical or ab initio methods. To determine stereochemical outcomes following pi-facial attack, ab initio calculations are required. Exo,endo stereoselectivities found experimentally, are successfully predicted by using RHF/6-31G*//3-21G or higher levels of calculations. Secondary orbital interactions are postulated to be responsible for the experimental stereoselectivities.

Item Type:	Article
Uncontrolled Keywords:	ab initio calculations; semiempirical calculations; cycloadditions; Diels-Alder reaction; dienes; functionalized cavity molecules; dimethyl acetylenedicarboxylate; norbornadiene; isobenzofurans; butadiene; systems; design; bonds
Subjects:	NATURAL SCIENCES > Chemistry
Divisions:	Division of Organic Chemistry and Biochemistry
Projects:	Project title Project leader Project code Project type Reaktivni meduprodukti u osnovnom i pobudenom stanju Mirjana Maksić 0098056 MZOS
Depositing User:	Davor Margetić
Date Deposited:	15 Nov 2013 12:20
URI:	http://fulir.irb.hr/id/eprint/950

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