Efficient One‐Step Synthesis of a Key Intermediate for the Synthesis of Azole Antifungals Using the Mitsunobu Protocol

A simple and single‐step process for coupling (2R,1S)‐1‐[2‐(2,4‐difluorophenyl)‐2‐oxiranyl]ethanol and various 1,2,4‐triazolones utilizing the Mitsunobu protocol is described. The product so formed is a key intermediate in the synthesis of azole antifungals with potent and broad‐spectrum activity against yeast and filamentous fungi.     

The First Total Synthesis of 4,4′-Biisofraxidin

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The First Synthesis of α-Methylene Isophosphindoline Oxide

Abstract

Over the last decade the intramolecular palladium-catalyzed coupling of haloarenes and haloalkenes with alkenes has proven to be a particularly valuable route to a wide variety of the structurally demanding cyclic and polycyclic systems We wish now to demonstrate its successhl application to the synthesis of the first parent representative of the five-membered ring carbon-phosphorus heterocycles possessing exocyclic unsaturation, a class of compounds remaining to date practically unexplored The effected synthesis of the a-methylene isophosphindoline oxide I is delineated in the equation which reveals also the optimized catalytic system and the prerequisite reaction conditions Of those, the reaction temperature is the most crucial parameter as the desired product undergoes unexpectedly facile thermal cyclodimerization to the spiropolycyclic system 2 frequently even precluding the isolation of 1.     

Efficient Method for The Synthesis of α-Amidophosphonates via the Michaelis-Arbuzov Reaction

Abstract

A new series of modified α-amidophosphonates (or β-ketophosphonate) was synthesized by an efficient method, starting from aminoesters and chloroacetyl chloride. We have established that chloroacetyl chloride is a suitable reagent allowing the introduction a halogen moiety for the Arbuzov reaction. The α-amidophosphonates were prepared in two steps (acetylation, phosphorylation).

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

An Efficient Protocol for the Liquid-Phase Synthesis of Furano- and Pyranoquinolines

In recent years, the liquid-phase synthesis of small heterocyclic molecules has been a subject of intense research activity, since it represents one of the most promising ways to generate small molecular libraries in the field of combinatorial chemistry. Substituted quinolines offer a high degree of structure diversity and have proven to be very important in medicinal chemistry.     

Efficient Protocol for the Synthesis of Novel Spiro[acenaphthylene-1,2′-pyrrolidin]-2-one Compounds

An efficient catalyst-free synthesis of 3′-benzoyl-4′,5′-diphenyl-2H-spiro[acenaphthylene-1,2′-pyrrolidin]-2-one derivatives via one-pot 1,3-dipolar cycloaddition of acenaphthenequinone, arylmethyl amines, and chalcones with high regioselectivity is described. The structure of the cycloadducts were characterized by infrared, high-resolution mass spectrometry (electrospray ionization), ¹H NMR, and ¹³C NMR spectra, and the structure of 4a was confirmed using x-ray single-crystal structure analysis.     

An Efficient Method for the Synthesis of Aliphatic α-Organothio Aldoximes

Theimportanceofthealiptlatica-organothioaldoxilnecompounds3inthepreparationofvariouspesticidesiswellestablished.Moleculescomprisingthea-organothiooximemoietyhavebeenreportedtoexhibitwiderangeofbiologicalactivities,Suchasinsecticidal.nematocidal,miticidalactivity1'2.Inthesynthesisofthecompounds3,thea-chlorinationofthecorrespolldingaliphaticaldoximeIisthekeystep.Inconventionalmethods.thealiphaticaldoximeIisa-chlorinatedbychlorine(CI=),thentheresultinghydroximeacidchloride2istreatedwithsodiumal…     

Improved Synthesis of 4,4′-Disubstituted-2,2′-Bipyridines

Ruthenium(II) tris(2,2′-bipyridine) complexes show interesting photochemical properties^1. Complexes containing substituents in the 4-and 4′-position of the 2,2′-bipyridine ligand have recently been used in systems which are aimed at the conversion and storage of solar energy^2,3. 2,2′-Bipyridine has a long history as a metal-chelating agent⁴. The use of 4,4′-disubstituted bipyridines as metal-chelating agents so far has been restricted probably because the reported syntheses of these compounds are rather laborious and the yields are low or moderate^5–8.     

A General and Efficient Protocol for the Synthesis of Biaryl Ethers from Aryl Silyl Ethers Using Cs2CO3

Biary ethers are known to be important organic compounds for their biological interests and great presence in life science industries. A number of them have consequently provide a strong incentive for synthesis, which includes the classical Ullman reaction, metal-catalyzed substitution, SN-Ar based type, intramolecular oxidative coupling and MW-assisted methods. Although the above synthetic strategies are particularly important, a method is required for the direct conversion of phenoxy silane to biaryl ethers without recourse to hydrolytic conditions.     

A Convenient Synthesis of 4,4′-Dimethylaminodiphenyl Diselenide and 4,4′-Dinitrodiphenyl Diselenide

A simple, rapid and efficient synthesis of 4,4′-dimethylamino-diphenyl diselenide 1 and 4,4′-dinitrodiphenyl diselenide 2 is described. The method consists of the reductive cleavage of the Se-CN linkage in the corresponding aryl selenocyanates by sodium borohydride followed by air oxidation of the resulting seleno-lates. The diselenides 1 and 2 are readily obtained in a state of high purity, in 89 and 80% yield, respectively.     

Efficient α-Thiocyanation of Ketones Using Pyridinium Hydrobromide Perbromide

Abstract

The direct α-thiocyanation of ketones with ammonium thiocyanate has been achieved using pyridinium hydrobromide perbromide under mild and neutral conditions to produce α-ketothiocyanates in excellent yields and with high selectivity.     

An Efficient Synthesis of Tertiaryaminomethylphosphonates,A Versatile Precursor for Synthesis of Glyphosate and α—Aminomethylphosphonates

Reaction of simple dialkyl phosphites with symmetrical 1,3,5-trisubstituted hexahydrotriazines (HHTs) in the presence of benzyl chloride,afforded tertiaryaminomethylphosphonates in excellent yields. Glyphosate,α-aminomethylphosphonates and their derivatives can therefore be synthesized by this procedure conveniently.     

An Efficient Synthesis of 4,4-Dimethyl 5-Methylene-γ-Butyrolactone

Cis^1a and -trans^1b Caronaldehyde acids are crucial intermediates for the synthesis of highly potent photostable pyrethroids like deltamethrin^1c and NRDC-182^1d. Recently these intermediates have been obtained by a total synthetic approach from 3, 4-dihydro-4, 4-dimethyl (2H)-pyran-2(one), know as DDP ^1b. The latter is prepared by a zeolite catalysed thermal rearrangement of 4, 4-dimethyl 5-methuylene-γ-butyrolactone (4). The lactone (4) is thus an important intermediate in the total synthtic sequence leading to potent pyrethroids.     

The First Total Synthesis of 16-Hydroxygeranylgeraniol

Facile synthesis of 16-hydroxygeranylgeranio 1,a naturally occurring alicyclic diterpene,by alkylation reaction of allylic iodide 3 with phenyl sulfone 4,is described.     

The First Total Synthesis of Saurufuran B

First total synthesis of saurufuran B 1, a furanoditerpene, from （E, E）-farnesol 2 and citraconic anhydride 3 through thirteen steps is described. Our work involves two key steps： （1） High regioselective alkylation of 2-（tert-butyldimethylsiloxy）-4-methylfuran 6 with aUylic iodides 5 in the presence of silver wifluoroacetate and （2） Conversion of substituted 7-1actone 7 into furan derivative 8.     

Facile Synthesis of 2,2′‐Dialkylated 4,4′‐Oxybiphenols

2,2′‐Alkyl‐disubstituted 4,4′‐oxybiphenols (4) were prepared in good yields through esterification of 4,4′‐oxybiphenol (1), AlCl₃‐promoted Fries rearrangement, and AlCl₃/NaBH₄‐promoted reduction reaction.     

Efficient Synthesis of Chiral 1,1′‐Sulfonyl Bisaziridines

An efficient three‐step synthesis of chiral 1,1′‐(sulfonyl)bisaziridines is described. Preparation of these compounds was carried out easily starting from N,N′‐sulfonyl bis‐(α‐L‐aminoester) to afford the title compounds in very good yields. These 1,1′‐(sulfonyl)bisaziridines can constitute interesting synthetic building blocks.     

Efficient Method for the Synthesis of α,α′-Bis(arylmethylidene) Cycloalkanones Catalyzed by Bromodimethylsulfonium Bromide

Bromodimethylsulfonium bromide (BDMS)–catalyzed crossed aldol condensation between aromatic aldehydes and ketones is reported to access α,α′-bis(arylmethylidene) cycloalkanones at room temperature in good yields within 3–10 min. The salient features of this method are the simplicity of the procedure, the ready accessibility of the catalyst, and greater yields in relatively short reaction times.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]