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Synthesis of New Thiophene‐Substituted 3,3‐Diphenyl‐3 H ‐naphtho[2,1‐ b ]pyrans by Cross‐Coupling Reactions, Precursors of Photomodulated Materials
Author(s) -
Frigoli Michel,
Moustrou Corinne,
Samat André,
Guglielmetti Robert
Publication year - 2003
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200300033
Subject(s) - chemistry , coupling reaction , thiophene , moiety , suzuki reaction , covalent bond , medicinal chemistry , naphthalene , grignard reaction , tetralone , derivative (finance) , photochemistry , organic chemistry , catalysis , reagent , palladium , financial economics , economics
3,3‐Diphenyl‐3 H ‐naphtho[2,1‐ b ]pyrans linked to one, two, or three thiophene nuclei in different positions of the naphthalene moiety (5, 6, 8, and 9) by a covalent bond have been prepared in good yields. A Suzuki cross‐coupling reaction was used with two possible strategies: chromenization before the coupling with oligothiophenes or chromenization after the coupling, the main intermediates being the diphenyl propargylic alcohol, the functionalized naphthol derivatives, and the thiophenic boronates. The overall yields for obtaining such photochromic compounds are generally quite satisfying. For the 7‐position, the coupling reaction has been realized using a Grignard reaction between a tetralone derivative and a thiophenic bromo magnesium intermediate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)