- An efficient palladium-catalyzed Negishi cross-coupling reaction with arylvinyl iodides: facile regioselective synthesis of E-stilbenes and their analogues
-
A general synthetic route for the Pd-catalyzed cross-coupling of an arylzinc reagent with arylvinyl iodides (Negishi cross-coupling) has been developed. The system permits efficient and selective preparation of E-stilbenes and their analogues. It also functions effectively at low levels of catalyst loading without the need for an additional ligand and tolerates a wide range of functional groups including heteroaromatic substrates. A systematic study of various parameters was performed and correlated with catalyst-substrate activity.
- Kabir, M. Shahjahan,Monte, Aaron,Cook, James M.
-
-
Read Online
- An Alternative Procedure in the Takai Reaction Using Chromium(III) Chloride Hexahydrate as a Convenient Source of Chromium(II)
-
An alternative procedure in the Takai reaction using chromium(III) chloride hexahydrate as the source of Cr(II) was performed. The use of zinc as Cr(III) reducer allowed us to carry out the iodovinylation of aldehydes in 63-99% yields. With the Garner and Dondoni aldehydes, these conditions along with a work-up using 4-t-butylpyridine allowed us to improve the yield of the corresponding vinyl iodide compared to the previous procedures.
- Auge, Jacques,Boucard, Valerie,Gil, Richard,Lubin-Germain, Nadege,Picard, Julien,Uziel, Jacques
-
-
Read Online
- Ionic liquid-induced conversion of methoxymethyl-protected alcohols into nitriles and iodides using [Hmim][NO3]
-
This Letter reports a one-pot efficient conversion of methoxymethyl-ethers into their corresponding nitriles and iodides using the ionic liquid, 1-methyl-3H-imidazolium nitrate ([Hmim][NO3]) under microwave irradiation. A variety of products were prepared in high yields using this method.
- Noei, Jalil,Mirjafari, Arsalan
-
-
Read Online
- On the mechanism and origin of the stereoselectivity in iodo-deboronation and chloro-deboronation of hindered alkenyl boronate esters using either ICl-NaOMe or ICl-pyridine
-
Conversion of hindered alkenyl boronate esters into the corresponding iodoalkene, or alkenyl chloride can be carried out stereoselectively using ICl. In the presence of NaOMe, direct reaction of ICl is favoured yielding the E-iodoalkene, however, the reaction with ICl followed by NaOMe can be used to give different major alkenyl iodide and chloride products, depending upon reaction temperature, ICl source and alkenyl boronate stereoelectronics.
- Lightfoot, Andrew P.,Twiddle, Steven J.R.,Whiting, Andrew
-
-
Read Online
- Trans-hydrometalation of alkynes by a combination of InCl3 and DIBAL-H: One-pot access to functionalized (Z)-alkenes
-
(equation presented) Triethylborane-induced hydrometalation of alkynes proceeds in an anti manner to afford the corresponding (Z)-alkenylmetal compounds stereoselectively, where dichloroindium hydride would play a key role. A variety of functional groups including hydroxy, carbonyl, and carboxy groups were tolerant under the reaction conditions. Following iodolysis and cross-coupling reaction of the (Z)-alkenylmetal species show the usefulness of this strategy.
- Takami, Kazuaki,Yorimitsu, Hideki,Oshima, Koichiro
-
-
Read Online
- Triethylborane-mediated hydrogallation and hydroindation: Novel access to organogalliums and organoindiums
-
Hydrogallation of carbon-carbon multiple bonds proceeds in the presence of triethylborane as a radical initiator. Several functionalities do not interfere with this reaction. Resulting alkenyl- and alkylgallium species can be trapped by several electrophiles. Highly regioselective radical addition of an indium hydride reagent to alkynes is also achieved. Various functionalities are tolerant under the reaction conditions. The reaction proceeds with complete anti stereoselectivity. Alkenylindiums obtained via hydroindation can be employed for the following cross-coupling reaction with aryl halides in one pot.
- Takami, Kazuaki,Mikami, Satoshi,Yorimitsu, Hideki,Shinokubo, Hiroshi,Oshima, Koichiro
-
-
Read Online
- Procedures for the nickel-catalyzed conversion of olefinic and cycloolefinic chlorides into iodides
-
A number of olefinic and cycloolefinic chlorides have been converted into the corresponding iodides by treatment with an excess of sodium iodide in dimethylformamide in the presence of bis(1,5-cyclooctadienyl)nickel or a mixture of nickel bromide and zinc
- Hooijdonk,Peters,Vasilevsky,Brandsma
-
-
Read Online
- Electrophilic Vinylation of Thiols under Mild and Transition Metal-Free Conditions
-
The iodine(III) reagents vinylbenziodoxolones (VBX) were employed to vinylate a series of aliphatic and aromatic thiols, providing E-alkenyl sulfides with complete chemo- and regioselectivity, as well as excellent stereoselectivity. The methodology displays high functional group tolerance and proceeds under mild and transition metal-free conditions without the need for excess substrate or reagents. Mercaptothiazoles could be vinylated under modified conditions, resulting in opposite stereoselectivity compared to previous reactions with vinyliodonium salts. Novel VBX reagents with substituted benziodoxolone cores were prepared, and improved reactivity was discovered with a dimethyl-substituted core.
- Castoldi, Laura,Di Tommaso, Ester Maria,Gr?fen, Barbara,Olofsson, Berit,Reitti, Marcus
-
p. 15512 - 15516
(2020/06/23)
-
- Dual nickel- and photoredox-catalyzed reductive cross-coupling of aryl vinyl halides and unactivated tertiary alkyl bromides
-
A novel reductive cross-coupling of aryl vinyl halides and unactivated tertiary alkyl bromides has been realized via photoredox/nickel dual catalysis to produce vinyl arene derivatives bearing all-carbon quaternary centers with excellent E-selectivity. A stoichiometric metal reductant could be avoided by employing commercially available N,N,N′,N′-tetramethylethylenediamine (TMEDA) as the terminal reductant.
- Yu, Weijie,Chen, Long,Tao, Jiasi,Wang, Tao,Fu, Junkai
-
supporting information
p. 5918 - 5921
(2019/05/27)
-
- Transition metal free large-scale synthesis of aromatic vinyl chlorides from aromatic vinyl carboxylic acids using bleach
-
While continuing our research on Hunsdiecker reaction, we came across an interesting application of bleach, sodium hypochlorite (NaOCl) for decarboxylative chlorination reaction. The reaction is easily scaled up to 10 mmol. The reaction has good tolerance towards wide variety of functional groups. The reaction has mild conditions and gave relatively high chemical yield of the desired product.
- Hatvate, Navnath T.,Takale, Balaram S.,Ghodse, Shrikant M.,Telvekar, Vikas N.
-
p. 3892 - 3894
(2018/10/02)
-
- Copper-mediated aerobic iodination and perfluoroalkylation of boronic acids with (CF3)2CFI at room temperature
-
The copper-mediated aerobic reactions between the branched (CF3)2CFI and boronic acids (R-B(OH)2) are described. Different from the linear perfluoroalkyl analogs CF3(CF2)nI (n?=?2, 3, 5, 7), (CF3)2CFI reacting with R-B(OH)2at room temperature under air in the presence of catalytic Cu powder provided exclusively the corresponding iodides (R-I), while the aerobic reactions of arylboronic acids with (CF3)2CFI at room temperature in the presence of Cu(OAc)2gave the perfluoroalkylation products (R-CF(CF3)2) in acceptable to moderate yields. The iodination reaction could be further promoted by hydroquinone, the addition of which improved the oxidation ability of (CF3)2CFI and provided the ipso-iodination products in high yields. The perfluoroalkylation was facilitated by the copper carboxylates since the addition of these salts into the reaction mixtures could successfully give rise to Ar-CF(CF3)2.
- Liu, Xi-Hai,Leng, Jing,Jia, Su-Jiao,Hao, Jian-Hong,Zhang, Fanglin,Qin, Hua-Li,Zhang, Cheng-Pan
-
-
- A simple and practical method for the stereoselective synthesis of (Z)-1-iodo-1-alkenes from 1,1-diiodo-1-alkenes
-
Treatment of the 1,1-diiodo-1-alkenes 8, prepared from the corresponding aldehydes with CI4/PPh3, with Zn-Cu/AcOH in THF-MeOH gave the (Z)-1-iodo-1-alkenes 9, selectively, in good yields.
- Kadota, Isao,Ueno, Hirokazu,Ohno, Akio,Yamamoto, Yoshinori
-
p. 8645 - 8647
(2008/04/18)
-