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1.
In a short reaction time, acyl chlorides and dry tetrahydrofuran react in the presence of a catalytic amount of magnesium turnings (Mg) at 25 °C to give 4-chlorobutyl esters in excellent yields.
2.
V. Srinivas 《合成通讯》2013,43(6):806-811
An efficient one-pot synthesis of 2-amino-5,10-dihydro-5,10-dioxo-4-phenyl-4H-benzo[g]chromene derivatives has been achieved by the reaction of 2-hydroxynaphthalene-1,4-dione, cyanothioacetamide, and aromaticaldehyde in EtOH at room temperature catalyzed by ZnCl2. The structures of the products were characterized by infrared, 1H NMR, mass, and elemental analysis.
3.
A reaction of SH-containing heterocycles with dimethyl carbonate (DMC) in the presence of K2CO3 and tetrabutylammonium bromide (Bu4NBr) gave heteroaryl methyl thioethers in 44–93% yields. The reaction was carried out under mild conditions. This method provided a useful synthetic method for preparation of various heteroaryl methyl thioethers without the use of toxic methylic halides or dimethyl sulfate.
4.
A protocol has been developed for the synthesis of the linear naphthopyran 16, by the TiCl4-catalyzed isomerization of 2,5-dimethyl dioxolane 1, having a methoxy group at position 1′ and a bromine atom at position 4′ of the naphthyl precursor to favor isomerization at position 2′.
5.
Oleksandr P. Dacenko Olga V. Manoylenko Pavel K. Mykhailiuk Dmitriy M. Volochnyuk Oleg V. Shishkin 《合成通讯》2013,43(7):981-992
An improved synthesis of Boc-monoprotected 5- and 6-amino-2-azanorbornanes is reported. The synthetic scheme consists of five steps and allows multigram quantities of the title compounds to be obtained. The regio- and stereochemistries of the products are established by two-dimensional NMR experiments.
6.
A new synthesis of 3-methoxypropanal from glycerol was presented. With this new approach, the conversion of glycerol to 3-methoxypropanal can be effected in moderate yield using catalysts of copper sulfate and polyethylene glycol (PEG).
7.
The selective and efficient acetylation of the hemiacetal hydroxyl in the equilibrium mixture between RCl2C(OAll)OH and AllOH/RCl2CHO was achieved using the acylating system Ac2O/Et3N/dimethylaminopyridine (DMAP).
8.
Daniel R. Zuidema Sarah L. Williams Katherine J. Wert Karin J. Bosma Abigail L. Smith Robert C. Mebane 《合成通讯》2013,43(19):2927-2931
Aryl ketones are readily deoxygenated to their corresponding aryl alkanes upon treatment with Raney nickel catalyst in boiling 2-propanol.
9.
Abdullah Saad Al-Bogami 《合成通讯》2013,43(19):2952-2958
Reaction of 2-acetyl-1-naphthol with aliphatic amines under microwave irradiation gave the corresponding imines (Schiff bases), which were treated with triphosgene to give 4-methylene-1,3-naphthoxazines in good yields.
10.
By grinding 1,2-dialkoxybenzene with anhydrous FeCl3 powder using a glass pestle in a mortar at ambient temperature under solvent-free conditions, hexaalkoxytriphenylenes were obtained in good yield (up to 90%) in 30 min. The solvent-free oxidative coupling reaction is a facile, efficient, “green-chemistry” method.
11.
A general, simple, and environmentally friendly method for the direct amination of secondary benzyl alcohols with amides or 4-nitroaniline is described. This method has been applied to a variety of substrates, and the reaction proceeded smoothly at room temperature under solvent-free conditions. CbzNH2 was proved to be very useful in the direct preparation of the benzylic amines from corresponding alcohols.
12.
A practical method for the synthesis of carbamates from ureas and organic carbonates was developed with 100% atom economy using La2O3/SiO2 as catalyst without any additional solvent. The scope of the protocol is demonstrated in the synthesis of 14 carbamates with various functional groups in excellent yields (76–95%).
13.
Trimethylsilyl iodide (TMSI) was found to be an efficient catalyst for the vinylogous Mukaiyama aldol reaction of 2-(trimethylsilyloxy)furan with various aldehydes with good diastereoselection. The reaction proceeds rapidly in CH2Cl2 affording the corresponding 5-(hydroxy(aryl)methyl)furan-2(5H)-ones in good yields. This method offers significant advantages such as efficiency, generality, and mild reaction conditions with shorter reaction time.
14.
The dehydration of aldoximes and amides, and oxidation of benzoin are accomplished in one-pot using in situ–generated Burgess-type reagent.
Keywords: Amide, benzil, benzoin, Burgess reagent, Burgess-type reagent, dehydration, nitrile, oxidation, oxime
15.
An efficient asymmetric synthesis of (S)-methyl 3-[4-[2-hydroxy-3-(isopropyl amino) propoxy] phenyl] propanoate is described. The key intermediate (S)-methyl 3-[4-(oxiran-2-ylmethoxy) phenyl] propanoate was obtained by hydrolytic kinetic resolution method using Jacobsen catalyst.
16.
Recyclable Siloxy Serine Organocatalyst for the Direct Asymmetric Mannich Reactions in Ionic Liquids
Fui-Fong Yong 《合成通讯》2013,43(9):1293-1300
A recyclable siloxy-L-serine organocatalyst has been developed to catalyze the asymmetric direct three-component Mannich reactions in ionic liquid hmim[PF6], furnishing the β-amino carbonyl scaffold in high enantio- and diastereoselectivities. The direct Mannich reaction between a selection of aromatic aldehydes and ketones resulted in good yields and high enantioselectivities.
17.
Several Brønsted acidic functional ionic liquids (FILs) with an alkane sulfonic acid group were synthesized. These FILs as dual solvent-catalysts for Nipagin esterification reactions were investigated. The results indicated that [HSO3-pMIM]HSO4 has the best catalytic activity and recyclability among the various kinds of FILs investigated, and its structure was characterized by infrared and NMR. The [HSO3-pMIM]HSO4 could be easily separated from the reaction mixture and reused without noticeably decreasing the catalytic activity.
18.
An efficient one-pot synthetic strategy for 2-aminobenzoxazoles was developed from isothiocyanates and 2-aminophenol using triflic acid as a cyclodesulfurizing reagent.
19.
Kaushik C. Chunavala 《合成通讯》2013,43(12):1843-1851
Iodine- and InCl3-catalyzed facile syntheses of 1,5- and 1,8-naphthyridines from 3-aminopyridine and 2-aminopyridines are described. The catalyst InCl3 could be recovered and reused up to five times efficiently.
20.
Synthesis of dibenzoxanthenes through condensation of β-naphthol with various aromatic and aliphatic aldehydes in ethanol as an ecofriendly solvent using RuIII as catalyst is reported.