The synthesis of sterically demanding amino acid-derived cyclic phosphonamides

The preparation and utilization of C(2)-symmetric 1,4-diamines in the synthesis of amino acid-derived cyclic phosphonamides 1-3 are described. The 1,4-diamines are synthesized via three methods: (i) amino acid/fumaryl chloride coupling followed by amide reduction, (ii) amino acid/1,4-diamine coupling followed by amide reduction, and (iii) a template-supported ring-closing metathesis/hydrolysis sequence. The pseudo C(2)-symmetric cyclic phosphonamides 1-3 are prepared by condensation of the C(2)-symmetric 1,4-diamines to P(III) centers, followed by oxidation.     

A concise route to structurally diverse DMP 323 analogues via highly functionalized 1,4-diamines

[reaction: see text] The utility of functionalized 1,4-diamines, produced via a temporary phosphorus tether (P-tether)/ring-closing metathesis (RCM)/hydrolysis sequence, is demonstrated in the synthesis of structurally diverse DMP 323 analogues. These 1,4-diamines are transformed into various seven-membered heterocycles via insertion of the appropriate nuclei "X". Subsequent derivatization generates heterocyclic diols that are similar in structure to DMP 323, a notable member of a class of highly potent inhibitors of HIV protease.     

Thiophene-thiophene versus phenyl-phenyl coupling in 2-(Diphenylamino)-Thiophenes: an ESR-UV/Vis/NIR spectroelectrochemical study.

The oxidation of several 2-diphenylamino-substituted thiophenes and N,N'-bis(2-diphenylamino-5-thienyl)-substituted phenylene-1,4-diamines with different substitution patterns in the 5-position of their thiophene moieties was studied by cyclovoltammetric and spectroelectrochemical measurements (ESR, UV/Vis/NIR). These measurements revealed both the structure of the oxidation products obtained and that of their cationic intermediates, as well as the pathway of their formation and follow-up reactions. Thus, the formation of the radical cations in the first electrochemical oxidation step of the target molecules was demonstrated. Depending on the substitution pattern, these radical cations give rise to several consecutive processes to a different extent. Thus radical dimers, dehydrodimers with a 2,2-bithiophene, 3,3'-bithiophene, or benzidine structure, as well as radical monocationic and dicationic products can be formed. For N,N'-bis(2-diphenylamino-5-thienyl)-substituted phenylene-1,4-diamines rather stable radical cations and dications were primarily formed and unambiguously identified. These species were transformed into 2,2'-bithiophene dimers and oligomers when the 5-position of the thiophene moiety was unsubstituted. By in situ spectroelectrochemistry the influence of the substituents on the type of coupling reactions can be demonstrated and followed in detail.     

Synthesis of N,N′-Bis(arylsulfanyl)cyclohexa-2,5-diene-1,4-diimines and N,N′-(Cyclohexa-2,5-diene-1,4-diylidene)bis(arenesulfinamides)

Russian Journal of Organic Chemistry - Reactions of (chlorosulfanyl)benzenes with benzene-1,4-diamines afforded new N,N′-bis(arylsul­fanyl)cyclohexa-2,5-diene-1,4-diimines which were...     

Expedient synthesis of chiral 1,2- and 1,4-diamines: protecting group dependent regioselectivity in direct organocatalytic asymmetric Mannich reactions

[reaction: see text] Organocatalytic asymmetric Mannich reaction of protected amino ketones with imines in the presence of an L-proline-derived tetrazole catalyst afforded diamines with excellent yields and enantioselectivities of up to 99%. The amino ketone protecting group controlled the regioselectivity of the reaction providing access to chiral 1,2-diamines from azido ketones and 1,4-diamines from phthalimido ketones.     

Reaction of 1,2-diamines with 4-hydroxycoumarin. Synthesis of 1,4-diazepin-5-ones

1,4-diazepin-5-ones were obtained from 4-hydroxycoumarin and substituted 1,2-diamines by heating in 2-methyl-1-propanol.     

Straightforward access to pyrazines, piperazinones, and quinoxalines by reactions of 1,2-diaza-1,3-butadienes with 1,2-diamines under solution, solvent-free, or solid-phase conditions

The preparation of tetrahydropyrazines, dihydropyrazines, pyrazines, piperazinones, and quinoxalines by 1,4-addition of 1,2-diamines to 1,2-diaza-1,3-butadienes bearing carboxylate, carboxamide, or phosphorylated groups at the terminal carbon and subsequent internal heterocyclization is described. The solvent-free reaction of carboxylated 1,2-diaza-1,3-butadienes with the same reagents affords piperazinones, while phosphorylated 1,2-diaza-1,3-butadienes yield phosphorylated pyrazines. The solid-phase reaction of polymer-bound 1,2-diaza-1,3-butadienes with 1,2-diamines produces pyrazines.     

手性1，4-二胺构建的双核铜[2+2]席夫碱大环化合物：制备和催化研究

Dinuclear copper(Ⅱ) complexes of [2+2] macrocyclic Schiff bases have been prepared from chiral 1,4-diamines using sodium ions as template. Catalytic investigation on the titled complexes has been carried out on model reactions (asymmetric sulfoxidation and asymmetric oxidative-coupling reactions).     

Divergent regioselective synthesis of 2,5,6,7-tetrahydro-1H-1,4-diazepin-2-ones and 5H-1,4-benzodiazepines

A novel and simple one-pot synthesis of 3-substituted 2,5,6,7-tetrahydro-1H-1,4-diazepin-2-ones from 1,2-diaza-1,3-dienes (DDs) and N-unsubstituted aliphatic 1,3-diamines is described. Here we also report a procedure to selectively obtain alkyl 5H-1,4-benzodiazepine-3-carboxylates from the DDs and 2-aminobenzylamine. Both processes occur by means of sequential 1,4-conjugated addition followed by regioselective 7-exo cyclization. The behavior of N-methyl- and N,N'-dimethyl-1,3-diaminopropanes toward the DDs furnished pyrazol-3-ones and bis-α-aminohydrazones, respectively.     

Asymmetric hydrogenation of isobutyrophenone using a [(Diphosphine) RuCl2 (1,4-diamine)] catalyst

[reaction: see text] The use of three chiral 1,4-diamines in the [(diphosphine) RuCl(2) (diamine)] catalyst system is demonstrated in the hydrogenation of acetophenone. The use of a 1,4-diamine offers unique properties that allow tuning of the catalyst system. These include the first example of the use of a racemic diamine in combination with a chiral phosphine, which gives 95% ee in the hydrogenation of isobutyrophenone.     

The reaction of aromatic dialdehydes with enantiopure 1,2-diamines: an expeditious route to enantiopure tricyclic amidines

The condensation of enantiopure 1,2-diamines with terephthalaldehyde, isophthalaldehyde or 2-iodo-, 2-alkyl- or 2-aryl-1,3-benzenedialdehydes in toluene followed by treatment with NBS in dichloromethane gives direct access to enantiopure 1,4-, and 1,3-di(4,5-dihydro-1H-imidazol-2-yl)benzenes (diamidines). The condensation of o-phthalaldehyde, and other ortho-disubstituted aromatic dialdehydes, with enantiopure 1,2-diamines, without NBS, gives enantiopure 3,5-dihydro-2H-imidazol-[2,1]-isoindoles.     

Synthesis of β-Diamine Building Blocks by Photocatalytic Hydroamination of Enecarbamates with Amines,Ammonia and N−H Heterocycles

3-Amino-substituted saturated nitrogen heterocycles are an important subclass of β-diamines, appearing in a number of clinical agents. Herein, we report a unified approach to these products based upon the regioselective photoredox-mediated hydroamination of enecarbamates. The amine coupling partner can encompass diverse amine types under a single set of reaction conditions, including primary alkyl amines, ammonia, aryl and heteroaryl amines, and N−H heterocycles. The method enables the synthesis of a wide range of pharmaceutically relevant building blocks.     

Synthesis of zwitterionic compounds: fully saturated pyrimidinylium and 1,3-diazepinylium derivatives via the novel rearrangement of 3-oxobutanoic acid thioanilide derivatives

An unusual rearrangement following cyclization of 2-anilino-2-ethoxy-3-oxothiobutanoic acid with aliphatic 1,3- as well as 1,4-diamine leads to zwitterionic derivatives of 2-hydroxypropanoic acid. Moreover, with aromatic 1,2-diamines, fused heterocyclic systems such as pteridine, quinoxaline, and pyrido[2,3-b]pyrazine are obtained.     

Effects of static and dynamic perturbations on isotropic hyperfine coupling constants in some quinone radicals

The effects of solvent dielectric response on the isotropic hyperfine coupling constants of the 1,4-benzoquinone, 1,4-naphthoquinone and 9,10-anthraquinone anions and 1,4-naphthalenediol cation radicals were studied by electron spin resonance (ESR) spectroscopy and by the theoretical density functional method within the polarizable continuum model. Experimental results demonstrate that the isotropic hyperfine coupling constants can be obtained with high accuracy and that the effects of solvent impurities can be minimized by careful sample preparation. The results obtained correlate well with theoretical predictions from density functional theory calculations. For 1,4-naphthalenediol both the solvent dielectric response as well as rotational averaging of the hydroxy groups were calculated. The overall results highlight the importance of static and dynamic perturbations to the couplings and aid in the assignation process of the couplings to specific magnetic nuclei.     

DABCO catalyzed reaction of various nucleophiles with activated alkynes leading to the formation of alkenoic acid esters, 1,4-dioxane, morpholine, and piperazinone derivatives

The reaction of acids, alcohols, acylamides, 1,2-diols, 1,2-diamines or amino alcohols with activated alkynes catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) was systematically investigated. A series of unsaturated alkenoic acid esters or heterocycles were formed in the reaction of monobasic or dibasic nucleophiles in excellent yields, respectively.     

A convenient method for the synthesis of six-membered heterocyclic enaminones

Enaminones are widely employed in the synthesis of heterocycles, however heterocyclic enaminones and their use in the synthesis of more complex systems have been less studied. The reaction between 4-chloroacetylacetate and aliphatic or aromatic 1,2-aminoalcohols, 1,2-aminothiols or 1,2-diamines, yields in one pot a six-membered 1,4-heterocyclic system containing the enaminone moiety.     

Synthesis of 1,4-diazines by ring expansion of 1,3-diazines

Fully saturated piperazin-3-one and quinoxalin-3-one derivatives were prepared by reactions of 2-anilino-2-ethoxy-3-oxothiobutanoic acid anilide with aliphatic 1,2-diamines. An unusual ring expansion of the intermediate 1,3-diazines leads to 1,4-diazines. Moreover, quinoxalin-3-one derivatives from chiral trans-1,2-diaminocyclohexane were obtained with diastereoselectivity >95%.     

Synthesis of symmetric 1,4-diamino-2-butynes via a Cu(I)-catalyzed one-pot A3-coupling/decarboxylative coupling of a propiolic acid, an aldehyde, and an amine

A novel microwave-assisted approach for the one-pot Cu(I)-catalyzed A(3)-coupling/decarboxylative coupling (PA(2)-coupling) of a propiolic acid, an aldehyde, and an amine, resulting in the formation of diversely substituted 1,4-diamino-2-butynes,is described. It is noteworthy that this new multicomponent coupling provides an efficient access to introduce alkyl and aryl group at the 1,4-position of the 1,4-diamino-2-butynes.     

Synthesis of Quinoxalinophenazine Derivatives and Reaction of 3,12-Dimethylbenzo[a]quinoxalino-[2,3-c]phenazine with Mercury(Ⅱ) Bromide: Spectral and Structural Characterization

A new series of quinoxalinophenazine derivatives were synthesized in good yields by the reaction of 2,3-dibromonaphthalene-1,4-dione with different aryl-1,2-diamines in DMF as solvent at 120~130℃ or under reflux conditions. 3,12-dimethylbenzo[a]quinoxalino[2,3-c] phenazine with bidentate character reacts with mercury(II) bromide to give suitable crystals. All products were confirmed by IR, 1H and 13 C NMR, and the metal complex by single-crystal X-ray method. The crystal(C24H16Br2HgN4, Mr = 720.82) belongs to the triclinic system, space group P1 with a = 10.186(6), b = 10.421(6), c = 11.470(7) , α = 98.670(7), β = 95.069(7), γ = 109.831(7)o, V = 1119.4(12) 3, Z = 2, Dc = 2.139 Mg/m3, μ = 10.46 mm-1, F(000) = 676, R = 0.043 and wR = 0.115 for 3982 observed reflections with I 2σ(I).     

McMurry coupling of aryl aldehydes and imino pinacol coupling mediated by Ti(O-i-Pr)4/Me3SiCl/Mg reagent

Ti(O-i-Pr)₄/Me₃SiCl/Mg reagent mediated McMurry coupling of aryl aldehydes to biaryl olefins at near room temperature. This low valent titanium (LVT) reagent also mediated the coupling of aldimines to 1,2-diamines (imino pinacol coupling).