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1.
The treatment of tertiary and secondary allylic alcohols containing a terminal double bond, and their acetyl derivatives, with triphenylphosphine and iodine under mild conditions leads regiospecifically and in high stereoselectivity to the corresponding primary allylic iodides, which can react ‘in situ’ with diverse nucleophiles. Primary allylic alcohols and benzyl alcohols and acetates are also transformed into the corresponding iodides under these conditions. 相似文献
2.
A general and selective method for the direct amidation of secondary benzyl alcohols with both sulfonamides and carbamates is described. This method has been applied to a variety of substrates and the reaction proceeded smoothly at room temperature in the presence of 5 mol % molybdenum(V) chloride to give the desired products in good yields. 相似文献
3.
A simple, inexpensive, environmentally friendly and high yielding amidation reaction of benzylic and allylic alcohols with primary amides using a catalytic amount of FeCl3 (5 mol %) is described. Direct substitution of various amides such as benzamide, sulfonamide, acetamide and acrylamide is reported, and this method also works on a large scale in high yield. 相似文献
4.
Samuel M. Silvestre 《Tetrahedron》2007,63(11):2439-2445
Various allylic and benzylic substrates were selectively oxidized to the corresponding enones in good yields using sodium chlorite, either in combination with tert-butyl hydroperoxide in stoichiometric conditions, or associated with N-hydroxyphthalimide as catalyst. These oxidation reactions were effectively and economically performed under mild, transition-metal free conditions and therefore the dual challenge of cost effectiveness and benign nature of the processes was met with. 相似文献
5.
Shu-Su ShenVita Kartika Ying Shan TanRichard D. Webster Koichi Narasaka 《Tetrahedron letters》2012,53(8):986-990
In the presence of copper(I) chloride, tert-butyl 1-hydroxy-2-methyl-6-trifluoromethyl-1H-indole-3-carboxylate acted as a catalyst for the chemoselective aerobic oxidation of allylic and benzylic alcohols. A variety of primary and secondary allylic and benzylic alcohols were oxidized into the corresponding α,β-unsaturated carbonyl compounds in good yields without affecting non-allylic alcohols. 相似文献
6.
Heng LiuYa-Hui Wang Li-Li ZhuXiao-Xiao Li Wen ZhouZili Chen Wen-Xiang Hu 《Tetrahedron letters》2011,52(23):2990-2993
An efficient and environmentally benign method was developed to synthesize the benzocycles from phenyl substituted allylic acetates through gold catalyzed Friedel-Crafts type carbocyclization reaction. Different substitution patterns were investigated, which gave a series of benzocyclohexane derivatives in moderate to excellent yields. 相似文献
7.
[Structure: see text] A copper-catalyzed amidation of allylic and benzylic C-H bonds with both primary and secondary sulfonamides is described. The reaction is applicable to the coupling of a diverse set of hydrocarbon species with aryl, heteroaryl, and alkyl sulfonamides and is tolerant of a variety of functional groups. Mechanistic insight has been gained through the isolation of a benzylic acetate intermediate, which was demonstrated to undergo facile conversion to the substituted sulfonamide product under copper catalysis. 相似文献
8.
Bismuth(III) salts are efficient catalysts for the selective allylic oxidation using tert-butyl hydroperoxide. BiCl3 is especially effective and can be easily recovered and reused as BiOCl. Using BiCl3/K-10 as catalyst, an increase in the reaction rate was observed. 相似文献
9.
The FeCl2/K2CO3 catalyst system was developed successfully for the N-alkylation of sulfonamides with benzylic alcohols via borrowing hydrogen method. XPS analysis suggested a possible catalyst cycle between Fe(II) and Fe(0). Under the optimized condition, the scope of the protocol was demonstrated in 21 different alkylation reactions. High yields, in general >90%, are achieved in most cases. 相似文献
10.
Karine Tissot-Croset 《Tetrahedron letters》2004,45(39):7375-7378
Methyl Grignard undergoes highly regio (>90/10) and enantioselective (ee 91-96%) copper catalyzed allylic substitution on cinnamyl-type chlorides. CuBr (3%) and 3.3% of a chiral phosphoramidite ligand are sufficient for a complete reaction. The synthesis of a precursor of (+)-Naproxen is described. The reaction can be extended to alkyl substituted allylic chlorides (ee 72%). 相似文献
11.
The activation of C-O bonds in allylic acetates in water as a suspension medium has been accelerated by carrying out the reactions in the presence of platinum complexes associated with ligands. The platinum-catalyzed allylation of aminonaphthalenes using allylic acetates gave the corresponding N-allylic aminonaphthalenes in good yields. 相似文献
12.
Jean Le BrasJacques Muzart 《Tetrahedron letters》2011,52(41):5217-5219
According to experimental and literature data, the one-pot formation of allylic azides or sulfonamides from catalytic amounts of PdCl2, homoallylic alcohols and TMSN3 or TsNH2 occurs through CC migration followed by regioselective nucleophilic addition on the PdII-activated CC bond and β-OH elimination. 相似文献
13.
Motoi Kawatsura 《Tetrahedron letters》2008,49(33):4873-4875
The ruthenium-catalyzed highly linear selective allylic amination of monosubstituted allylic acetates with secondary amines was developed. The regioselectivity was controlled by the Ru3(CO)12/2-DPPBA catalyst, and a linear-type aminated product was obtained as a single regioisomer. 相似文献
14.
Stephen G. Davies Kenneth B. Ling Paul M. Roberts Angela J. Russell James E. Thomson Philip A. Woods 《Tetrahedron》2010,66(34):6806-6813
A stereodivergent protocol for the aziridination of a range of cyclic allylic amine derivatives has been developed. syn-Products can be obtained in >99:1 dr under H-bonded control and anti-products are obtained in >99:1 dr under steric control by judicious choice of the N-protecting groups. 相似文献
15.
Arylation of allylic acetates employing triarylbismuths as multi-coupling reagents under palladium-catalyzed conditions was reported. Triarylbismuths as nucleophilic coupling partners were used in sub-stoichiometric amounts with respect to allylic acetates and thus served as atom-efficient multi-coupling reagents. A variety of allylic acetates were cross-coupled with triarylbismuths to furnish the corresponding functionalized 1,3-disubstituted propenes in good to excellent yields in short reaction times. The reported palladium protocol also yielded chemo-selective allylic arylations in high yields. 相似文献
16.
17.
Olivier Rezazgui Benjamin BoënsKarine Teste Julien VergnaudPatrick Trouillas Rachida Zerrouki 《Tetrahedron letters》2011,52(50):6796-6799
This paper describes a one-pot procedure for acetamide synthesis directly from amines and pyrimidine ester, without any catalyst or coupling agents. The inexpensive and simple reaction conditions are the most important features of this amidation. This reaction was performed with various amines, showing that long range stabilizing interactions (H-bonding and π-stacking) are the driving force for chemoselectivity. 相似文献
18.
An efficient, selective and environmentally benign photocatalytic system in acetonitrile has been developed for aerobic oxidation of activated benzylic and allylic alcohols into their corresponding aldehydes and ketones without the need for a transition metal in moderate to excellent yields with a catalytic amount of iodine. Very high inter- and intramolecular chemoselectivities are observed when benzylic OH groups are oxidized in the presence of aliphatic (nonbenzylic) hydroxyls. 相似文献
19.
Sandip N.Gavade Ravi S.Balaskar Madhav S.Mane Pramod N.Pabrekar Murlidhar S.Shingare Dhananjay V.Mane 《中国化学快报》2011,22(6):675-678
The coupling reaction of phenylurea with different functionalized aryl halides in the presence of air stable CuI,N,N-dimethylethylenediamine as a ligand,and K3PO4 as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields.This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligands. 相似文献
20.
The copper-mediated trifluoromethylselenolation of propargylic chlorides and allylic bromides is described. This approach provides a wide range of propargylic and allylic trifluoromethyl selenoethers in moderate to good yields. These results open the way to synthesis strategies for various trifluoromethylselenolated compounds. 相似文献