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Alkoxycarbonylation of 3,3,3‐Trifluoropropyne: an Intriguing Reaction to Prepare Trifluoromethyl‐Substituted Unsaturated Acid Derivatives
Author(s) -
Scrivanti A.,
Beghetto V.,
Matteoli U.
Publication year - 2002
Publication title -
advanced synthesis and catalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.541
H-Index - 155
eISSN - 1615-4169
pISSN - 1615-4150
DOI - 10.1002/1615-4169(200207)344:5<543::aid-adsc543>3.0.co;2-u
Subject(s) - chemistry , trifluoromethyl , regioselectivity , yield (engineering) , medicinal chemistry , ligand (biochemistry) , catalysis , methanol , carboxylic acid , reaction conditions , selectivity , diphenylphosphine , organic chemistry , phosphine , receptor , biochemistry , alkyl , materials science , metallurgy
The addition of CO and methanol to 3,3,3‐trifluoropropyne is catalysed by Pd(OAc) 2 in the presence of (6‐methylpyrid‐2‐yl)diphenylphosphine and CH 3 SO 3 H. The main products of the reaction are the methyl esters of 2‐(trifluoromethyl)propenoic acid 1 and of 3‐(trifluoromethyl)propenoic acid 2 (4,4,4‐trifluorobut‐2‐enoic acid). The regioselectivity of the reaction can be controlled to a great extent by a suitable choice of the composition of the catalytic system and the reaction conditions. Thus, 1 can be obtained in 93% yield by using P (CO)=20 atm and high ligand/Pd and acid/Pd ratios. On the other hand, selectivity up to 85% in 2 can be achieved using P (CO)=80 atm and a low ligand/Pd ratio together with a high acid/Pd ratio. The reaction mechanism is also discussed.