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Titolo:
An investigation of the solid-state photochemistry of alpha-mesitylacetophenone derivatives: Asymmetric induction studies and crystal structure-reactivity relationships
Autore:
Cheung, E; Rademacher, K; Scheffer, JR; Trotter, J;
Indirizzi:
Univ British Columbia, Dept Chem, Vancouver, BC V6T 1Z1, Canada Univ British Columbia Vancouver BC Canada V6T 1Z1 ver, BC V6T 1Z1, Canada
Titolo Testata:
TETRAHEDRON
fascicolo: 36, volume: 56, anno: 2000,
pagine: 6739 - 6751
SICI:
0040-4020(20000901)56:36<6739:AIOTSP>2.0.ZU;2-G
Fonte:
ISI
Lingua:
ENG
Soggetto:
YANG PHOTOCYCLIZATION REACTION; CARBOXYLATE SALTS; ABSTRACTION; TRIPLETS;
Keywords:
photochemistry; cyclization; asymmetric induction;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Physical, Chemical & Earth Sciences
Citazioni:
24
Recensione:
Indirizzi per estratti:
Indirizzo: Scheffer, JR Univ British Columbia, Dept Chem, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada Univ British Columbia 2036 Main Mall Vancouver BC CanadaV6T 1Z1
Citazione:
E. Cheung et al., "An investigation of the solid-state photochemistry of alpha-mesitylacetophenone derivatives: Asymmetric induction studies and crystal structure-reactivity relationships", TETRAHEDRON, 56(36), 2000, pp. 6739-6751

Abstract

The photochemical conversion of a series of alpha-mesitylacetophenone derivatives into 2-indanols via delta-hydrogen abstraction has been investigated in the solid state. A correlation between solid-state reactivity and crystal structure has been established for this type of reaction. For the sevencompounds whose crystal structures were determined, the average value of d(C=O...H distance) and L (C=O...CH3 distance) were 2.77+/-0.04 Angstrom and 3.42+/-0.06 Angstrom, and the value of omega (delta-H out of plane angle), d (C=O...H angle) and a (C-H...O angle) were 59+/-2 degrees, 80+/-7 degrees and 123+/-3 degrees, respectively. These parameters depended mainly on the magnitude of the deviation of the carbonyl group from the fully bisecting position over the mesityl ring, which ranged from 9-14 degrees in the case of in the solid state reactive ketones and approached 0 degrees for the unreactive compounds. Asymmetric induction studies were carried out by providing the reactants with carboxylic acid substituents to which ionic chiral auxiliaries were attached through salt formation with optically active amines. Irradiation of the salts (13 in total) in the crystalline state gave enantiomeric excesses of up to 90%. The crystal structures of three of the salts were determined and on this basis, the reasons for the selectivity in the crystalline state are discussed. (C) 2000 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/09/20 alle ore 09:25:46