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1.
Sara Stas  Georges Laus 《Tetrahedron》2008,64(16):3457-3463
Potassium alkynyltrifluoroborates and potassium (2-phenyl)vinyltrifluoroborates react with N-3-butenyl-(2,2-dichloro-1-propylidene)amine in the presence of BF3·Et2O as a Lewis acid to synthesize rearranged Mannich products. The reaction starts with a cationic 2-aza-Cope rearrangement of the imine, followed by the Lewis acid promoted borono-Mannich-type reaction on the rearranged imine to result in a new class of functionalized N-homoallylamines.  相似文献   

2.
A series of 1,3-dioxanyl vinyl acetals were readily synthesized from the corresponding dioxanone by a reduction and in situ acylation followed by Petasis olefination. Treatment of these vinyl acetals with BF3·OEt2 results in an O to C rearrangement to form anti-3,5-dihydroxyketones while a mixture of Me3Al and BF3·OEt2 provides the corresponding syn relationship via a stereoretentive rearrangement.  相似文献   

3.
Wei Yuan 《Tetrahedron》2010,66(35):7104-12031
Vinylidenecyclopropanes undergo ring-opening reactions with xanthydrol in the presence of BF3·OEt2 or with xanthene in the presence of DDQ at 0 °C in 1,2-dichloroethane to give the corresponding conjugate triene derivatives in moderate to good yields. Plausible reaction mechanisms have been discussed on the basis of previous literature and the control experiments. The further transformation of these trienes has been disclosed in DCE in the presence of BF3·OEt2 along with a plausible reaction mechanism.  相似文献   

4.
Sara Stas 《Tetrahedron》2007,63(36):8921-8931
Potassium phenylethynyltrifluoroborate and potassium styryltrifluoroborates react with α,α-dichlorinated aldimines in the presence of BF3·OEt2 as a Lewis acid to give a new stable class of functionalized propargylamines and allylamines. The use of hexafluoroisopropanol as a co-solvent in this modified Petasis reaction allows high yield isolation of the target compounds.  相似文献   

5.
6.
A simple and efficient one-pot method for the synthesis of new 2,4-diaryl-1,2,3,4-tetrahydroquinolines using a three-component imino Diels-Alder cycloaddition between trans-isoeugenol or trans-anethole, anilines, and benzaldehyde in the presence of BF3·OEt2 in PEG-400, a green and reusable solvent, has been developed. Also, BF3·OEt2-catalyzed formal [3+2] cycloaddition reaction of trans-isoeugenol or trans-anethole with 1,4-benzoquinone in PEG-400 to give dihydrobenzo[b]furan derivatives has been described.  相似文献   

7.
The reaction of aromatic esters with alkynyllithiums in the presence of lithium morpholinide and BF3·OEt2 gave aromatic alkynyl ketones in good yield (78-87%).  相似文献   

8.
Aldehyde, homoallylic amine and arene undergo smooth cyclization in the presence of BF3·OEt2 to afford 4-arylpiperidines in good yields and with high trans-selectivity. This is the first report on the preparation of 4-arylpiperidines via aza-Prins-Friedel-Crafts reaction.  相似文献   

9.
The influence of fluorinated alcohols on the BF3·Et2O-promoted Ritter type reaction has been investigated. Trifluoroethanol/BF3·Et2O system allowed access to the central unit of protease inhibitors by the ring opening of fluorinated epoxide 2 with various nitriles.  相似文献   

10.
The aza-Cope rearrangement of N-allylanilines is described. The use of BF3·OEt2 and microwave irradiation allows to run the transformation under mild conditions and in reaction times of minutes.  相似文献   

11.
The direct oxidative cyclization of 3-arylpropionic acids using PIFA or Oxone is reported. In the presence of BF3·OEt2, the reaction of 3-arylpropionic acids with PIFA or Oxone proceeded smoothly at 30 °C to give 3,4-dihydrocoumarins in good to excellent yields.  相似文献   

12.
N-Bis(trimethylsilyl)methyl aldimines undergo nucleophilic addition reaction with premixed lithium alkynides/BF3·OEt2 to give moderate to good yields of N-bis(trimethylsilyl)methyl propargyl amines.  相似文献   

13.
A facile and operationally simple route to diastereomerically pure, natural-like 3-azabicyclo[3.3.1]non-6-enes via microwave-assisted, BF3·OEt2-promoted aza-Prins reaction has been developed. Complexity-generating transformations based on these products involving reactive functionalities introduced during the aza-Prins step have been developed.  相似文献   

14.
Boron trifluoride–etherate (BF3·OEt2) in 2,2,2‐trifluoroethanol (TFE) was found to be a highly efficient promoter system for the intramolecular alkyne–aldehyde metathesis of o-(3-arylpropargyloxy)benzaldehydes. The reaction produces the corresponding 3-aroyl-2H-chromenes in excellent yields under metal-free conditions.  相似文献   

15.
Yong Xin 《Tetrahedron》2008,64(39):9315-9319
Unexpected spiro cyclic products were formed from the reaction of imines and salicylaldehyde with silyl enol ethers in the presence of BF3·OEt2. Different kinds of dioxaspiro products were afforded depending on the nature of starting materials. Furthermore, salicylaldehyde could also react directly with several silyl enol ethers, giving three products with different spiro cyclic structure under the same reaction conditions.  相似文献   

16.
Several amides were obtained in high yields by an efficient method from the corresponding imines which are readily prepared from aldehydes. This procedure involves the oxidation of aldimines with m-CPBA and BF3·OEt2. In this reaction, the product is strongly influenced by the electron releasing capacity of the aromatic substituent.  相似文献   

17.
N,N-Difluoroboryl complexes of 3,3′-diarylazadiisoindolylmethenes were synthesized by the reaction of BF3·OEt2 and 3,3′-diarylazadiisoindolylmethenes, which were easily prepared from a reaction between phthalonitrile and aryl Grignard reagents. These novel dyes exhibit strong absorption in the visible region and intense fluorescence in the vis/NIR region. Their synthesis, characterization, and optical properties are reported in this Letter.  相似文献   

18.
Microwave-promoted synthesis of polyhydroxydeoxybenzoins in ionic liquids   总被引:1,自引:0,他引:1  
A microwave-promoted synthesis of polyhydroxydeoxybenzoins and -phenylpropanones has been developed, using bis{(trifluoromethyl)sulfonyl}amine (HNTf2) or BF3·OEt2 in an ionic liquid solvent.  相似文献   

19.
We have developed an efficient method to regioselectively deacetylate polyacetoxyacetophenones using BF3·OEt2 in excellent yields and demonstrated the application of the procedure in the synthesis of natural products.  相似文献   

20.
Lei WuMin Shi 《Tetrahedron》2011,67(32):5732-5739
BF3·OEt2-catalyzed intermolecular reactions of arylmethylenecyclopropanes with (E)-1,1,3-triarylprop-2-en-1-ols produced the corresponding triene compounds, alcoholic derivatives or cyclobutane derivatives in moderate to excellent yields under mild conditions.  相似文献   

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