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1.
A range of aryl chlorides undergoes cross-couplings with alkynes in good yields in the presence of [PdCl(C3H5)]2/cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as catalyst. A variety of aryl chlorides such as chloroacetophenone, chlorobenzonitrile, chloronitrobenzene, chloroanisole or chlorotoluene have been used successfully. The reaction also tolerates several alkynes such as phenylacetylene, dec-1-yne, ethynylcyclohexene or alk-1-ynols. Furthermore, this catalyst can be used at low loading with some substrates.  相似文献   

2.
A novel pathway for homocoupling of terminal alkynes has been described using cyclopalladated ferrocenylimine 1 or 2/CuI as catalyst in the air. This catalytic system could tolerate several functional groups. The palladacycle 2 in the presence of n-Bu4NBr as an additive could be applied to Sonogashira cross-coupling reaction of aryl iodides, aryl bromides, and some activated aryl chlorides with terminal alkynes under amine- and copper-free conditions, mostly to give moderate to excellent yields.  相似文献   

3.
Treatment of alkynes with ortho-formyl and acetyl phenylboronic acids in the presence of a cobalt catalyst resulted in the formation of 2,3-disubstituted indenols in good yields. When aryl silyl alkynes were used, 2-aryl-3-silyl indenols were obtained regioselectively in good yields.  相似文献   

4.
o-Iodophenols and o-iodoaniline derivatives react with terminal alkynes under 1 atm of CO in the presence of pyridine and catalytic amounts of Pd(OAc)2 to generate coumarins and 2-quinolones, respectively, as the only products. Terminal alkynes bearing alkyl, aryl, silyl, hydroxyl, ester and cyano substituents are effective in these processes affording the desired products in moderate yields. The formation of coumarins and 2-quinolones in this process is in stark contrast with all previously described palladium-catalyzed reactions of o-iodophenols or o-iodoanilines with terminal alkynes and CO, which have afforded chromones and 4-quinolones. Moreover, under our reaction conditions terminal alkynes insert into the carbonpalladium bond instead of undergoing a Sonogashira-type coupling as confirmed by an isotope labeling experiment.  相似文献   

5.
An electron-deficient [CpERhCl2]2 catalyzed annulation of N-pentafluorophenylbenzamides with internal alkynes was successfully established under mild reaction conditions, with the assistance of Lewis acid silver salt. Particularly, electron-deficient benzamide substrates were smoothly transformed into the desired products in this catalytic system. The catalytic system showed a broad tolerance for different substituents on the aromatic rings or aryl, alkyl-substituted alkynes.  相似文献   

6.
The nickel catalyzed, palladium/phosphine free carbonylative Sonogashira reaction of terminal alkynes with substituted aryl and heteroaryl iodides is described. This protocol provides mild and robust conditions to synthesize a variety of substituted aryl α,β-alkynyl ketones and flavones in good to excellent isolated yields. This methodology tolerates several functional groups such as electron donating (methyl, isopropyl, tert-butyl, methoxy) as well as electron withdrawing (trifluoromethyl, nitro, esters, nitrile) groups on the terminal alkynes and iodides.  相似文献   

7.
An unprecedented rhodium(III)‐catalyzed hydroarylation of α,α‐difluoromethylene alkynes with N ‐pivaloxyl aroylamides through sequential C−H activation and aryl migration is detailed herein. A large array of α,α‐difluoromethylene alkynes and N ‐pivaloxyl aryl amides were amenable to this transformation, thus providing a novel synthetic protocol for the construction of difluorinated 2‐alkenyl aniline derivatives in high yields and with excellent regioselectivity. Notably, unique fluorine effects were found to underlie the thus unconventional reaction manifold.  相似文献   

8.
Manojit Pal 《Tetrahedron letters》2003,44(45):8221-8225
An efficient synthesis of 2-alkyl/aryl substituted benzo[b]furans/nitrobenzo[b]furans in water has been accomplished via Pd/C catalyzed reaction of o-iodophenols with terminal alkynes in the presence of PPh3, CuI and prolinol. This method can tolerate a variety of functional groups present in the alkynes as well as base labile nitro group in the o-iodophenols. The protocol does not require the use of a phase transfer catalyst or water-soluble phosphine ligands and is free from the use of any organic co-solvent.  相似文献   

9.
Hydroamination and hydrothiolation are the most efficient and completely atom-economical process to construct important enamine and vinyl sulfide intermediates in pharmaceutical and organic chemistry. The cyclic trimeric phosphazene base (CTPB) showed great catalytic activity for the anti-Markovnikov stereoselective hydroamination and hydrothiolation of alkynes in good to excellent yields. A broad substrate scope of alkynes and nucleophiles was demonstrated, including aryl and heteroaryl alkynes, terminal and internal alkynes, different N-heterocycles, thiols and thiophenols. This versatile and cost-efficient approach with good stereoselectivity and excellent functional group tolerance provided new opportunity for the organocatalyzed hydrofunctionalization of alkynes.  相似文献   

10.
(Z)-exo-Glycals can be conveniently prepared in a convergent manner by Stille cross-coupling of (Z)-halo(Br,I)-exo-glycals and aryl or alkenyl stannanes, the latter are readily obtained by addition of tributylstannyl radicals to terminal alkynes.  相似文献   

11.
3-Iodo-4-chalcogen-2H-benzopyran derivatives underwent a direct Sonogashira cross-coupling reaction with several terminal alkynes in the presence of a catalytic amount of Pd(PPh3)2Cl2 with CuI as a co-catalyst, using Et3N as base and solvent. This cross-coupling reaction proceeded cleanly under mild conditions and was performed with propargylic alcohols, propargylic ethers, as well as alkyl and aryl alkynes, furnishing the correspondent 3-alkynyl-4-chalcogen-2H-benzopyrans in good yields.  相似文献   

12.
An efficient synthesis toward highly diversified δ-carbolines via one-pot multicomponent reaction using N-Boc-3-amido indoles, aryl aldehydes, and aromatic terminal alkynes under microwave conditions has been described.  相似文献   

13.
Yasutaka Yatsumonji 《Tetrahedron》2006,62(42):9981-9987
(E)-Alkenyl halides were transformed into (E)-alkenyl sulfides by the nickel(0) triethyl phosphite complex-catalyzed reaction with thiols, whereas (Z)-alkenyl halides gave alkynes under the same reaction conditions. Aryl halides were also transformed into aryl sulfides using the same reagent system.  相似文献   

14.
A nickel(II)-catalyzed alkynylation/annulation of aryl carboxamides assisted by an N, S-bidentate directing group with terminal alkynes is described. This protocol provides an effective method to selectively furnish a series of biologically 3-methyleneisoindolin-1-one derivatives bearing methylthio group. Various carboxamides and terminal alkynes with a number of functional groups were compatible in this reaction to afford the corresponding products in moderate to good yields.  相似文献   

15.
Nitin S. Nandurkar 《Tetrahedron》2008,64(17):3655-3660
Palladium bis(2,2,6,6-tetramethyl-3,5-heptanedionate): a structurally well-defined O-containing transition metal complex is reported as an efficient catalyst for Suzuki, Heck, and Sonogashira cross-coupling reactions. The protocol was also applied successfully for cyanation of aryl halides under milder operating conditions. The system tolerated the coupling of various aryl halides with alkenes, alkynes, and organoboronic acid along with the cyanation of aryl halides providing good to excellent yields of desired products.  相似文献   

16.
The metal complex Rh(acac)(CO)2 in the presence of an eqimolar amount of tris(o-methoxyphenyl)phosphine provides a useful catalyst system for the 1,4-addition of alkynes to unsubstituted vinyl ketones. Best yields are obtained when the transformation is performed in benzene at reflux with an excess of vinyl ketone. Both aryl and alkyl substituted alkynes participate in the reaction. Primary alcohols and alkyl chlorides are well tolerated under these reaction conditions. The reaction also proceeds in aqueous solvent mixtures, unlike most organometallic addition reactions.  相似文献   

17.
Conditions for a FeCl3/PPh3-catalyzed and palladium-, copper-, amine free-Sonogashira coupling reaction of aryl halides with terminal alkynes are reported. The protocol was applicable to a wide variety of substituted aryl iodides and alkynes with different steric and electronic properties and gave excellent yields of the desired coupling products.  相似文献   

18.
The water-soluble Pd-salen complex, palladium(II) N,N′-bis{[5-(triphenylphosphonium)methyl]salicylidene}-1,2-ethanediamine chloride, is a highly active catalyst for the copper-free Sonogashira coupling of aryl iodides with terminal alkynes in water under aerobic conditions.  相似文献   

19.
Vito A. Fiore  Gerhard Maas 《Tetrahedron》2019,75(26):3586-3595
N-Trifluoromethylsulfonyl-propiolamides have been prepared by two methods: a) N-triflation of secondary acetylenic carboxanilides, prepared in two steps from terminal alkynes, with triflic anhydride (Tf2O) and b) from terminal alkynes and an aryl or alkyl isocyanate followed by Tf2O in a consecutive one-pot reaction. The title compounds are bench-stable and insensitive to water and alcohols but amenable to transamidation reactions with a wide range of amine nucleophiles. Conversely, they are excellent reagents for the propynoylation of ammonia, primary and secondary amines, anilines, and hydrazines.  相似文献   

20.
In InCl3-NaBH4-MeCN system, terminal aryl alkynes could couple with aryl iodides and bromides to give disubstituted alkenes via hydroindation of CC. In the similar way, (E)-alkenylsilanes were synthesized via reduction of alkynylsilanes in tetrahydrofuran (THF) in high yields. The processes showed high regio- and stereoselectivity.  相似文献   

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