- Al(OTf)3: An efficient lewis acid additive for domino addition-elimination of Grignard reagents to activated ketones
-
It has been demonstrated that aluminium triflate in either stoichiometric or catalytic quantities facilitates the addition-elimination of Grignard reagents to electron-rich ketones, such as methoxy substituted acetophenones, propiophenone and chromanone in a one-pot process, and that it has an enhancing effect on the addition of these reagents to the ketones. It has also been found that the reactions are highly stereoselective towards one regioisomer of the alkene in the case of oxygenated aryl-alkyl substituted substrates, but not when the elimination originates from a double benzylic alcohol intermediate.
- Pieterse, Tanya,Visser, Melanie,Marais, Charlene,Bezuidenhoudt, Barend C. B.
-
supporting information
p. 1541 - 1546
(2016/06/14)
-
- Synthesis of 1,1-diarylethylenes
-
A facile route toward 1,1-diarylethylenes 6 has been developed in good yields via mCPBA-promoted oxidation of β-hydroxysulfides 2, BF3·OEt2-mediated Friedel-Crafts reaction of the resulting β-hydroxysulfoxides 3 with oxygenated benze
- Chang, Meng-Yang,Huang, Yi-Hsuan,Wang, Heui-Sin
-
p. 3022 - 3031
(2016/05/19)
-
- Mechanistic studies of photohydration of m-hydroxy-1,1-diaryl alkenes
-
The photohydration of a variety of m-hydroxy-1,1-diaryl alkenes (8-10) and related systems (11 and 12) has been studied in aqueous CH3CN solution. All of these alkenes photohydrate efficiently in 1:1 H2O-CH3CN, to give the corresponding 1,1-diarylethanol (Markovnikov addition) products with high chemical and quantum yields. The aim of this study was to further probe the mechanism of photohydration reported for the parent m-hydroxy-α-phenylstyrene (5), which has been proposed as consisting of a water trimer-mediated excited state (formal) intramolecular proton transfer (ESIPT) from the phenolic proton to the β-carbon of the alkene moiety to give an observable (by laser flash photolysis (LFP)) m-quinone methide intermediate 6. For this purpose, derivatives of 5 with substituents (methyl or methoxy) on the α-phenyl ring as well as related model compounds were explored. Product studies, quantum yields, fluorescence, and nanosecond laser flash data are reported that are consistent with two distinct mechanisms for photohydration of these compounds: one involving water-mediated ESIPT (8, 9), as observed for the parent compound 5, and one involving direct protonation of the β-carbon by solvent water (11 and 12), with compound 10 possibly operating via both mechanisms.
- Cole, John G.,Wan, Peter
-
-
- ARYLALKENYLATION OF DIMETHOXYBENZENES WITH PHENYLACETYLENE
-
During the arylalkenylation of dimethoxybenzenes with phenylacetylene in the presence of the catalysts H3PO4*BF3, KU-2, and (C2H5)2O*BF3 α-arylstyrenes or their cyclodimers derivatives of indane (from 1,2- and 1,4-dimethoxybenzenes) or derivatives of ind
- Zinov'eva, L.V.,Ryabov, V.D.
-
p. 540 - 545
(2007/10/02)
-