cis-3-芳脲基-2-苯基-2-氧代萘并[1,2-d]-1,2-氧膦杂环戊烷合成

利用2-羟基-1-萘甲醛、芳基脲、苯基二氯化膦作为起始原料,在无水甲苯中反应合成cis-3-芳脲基-2-苯基-2-氧代萘并[1,2-d]-1,2-氧膦杂环戊烷.产物结构经IR,1HNMR,31PNMR和元素分析等进行了表征.     

Synthesis of a new conformationally defined serotonin homologue by intramolecular [4+2] cycloaddition

Treatment of 1-[(p-methoxyphenyl)sulfonyl]-2-methyl-3-[N-allyl-N-methyl-3-(2,6-dichlorobenzoyl)propylamino]indole 3 with triethylamine in chlorobenzene at 135°C results in the formation of 1,2,3,4,4a,5,6,11c-octahydro-7-[(p-methoxypyhenyl)-sulfonyl]-3-methyl-7H-pyrido[3,4-c]carbazole 1b in 58% yield. The reaction is selective in giving predominantly the trans isomer.     

Synthesis and intramolecular reactions of trans-cyclohexyl-1,2-bisacrylate

Photocycloaddition of dimethyl cyclobut-1-ene-1,2-dicarboxylate (1) with cyclohexene (7) afforded two photoadducts 8 and 9 in 44% and 28% yields, respectively. Spontaneous thermal isomerization of 8 gave (4Z,10Z)-dimethyl cyclodeca-4,10-diene-1,4-dicarboxylate (10), which subsequently isomerized to produce trans-1,2-cyclohexanebis-alpha-acrylic acid dimethyl ester 11. Hydride reduction of the bisacrylate 11 gave the trans-octahydro-1H-inden-2-ols 12a and 15 via a novel, stereoselective, intramolecular reaction. Reaction of the bisacrylate 11 with methyllithium afforded the bis-tertiary alcohol 16. In contrast, lithium dimethylcuprate reacted with the bisacrylate 11 to give the trans-hexahydro-1H-inden-2-one 17 in high yield via a novel, stereoselective, intramolecular reaction.     

Synthesis of 5-Substituted Hexahydro-1H-1, 4-Diazepine Analogues

Searching for new analgesic is still of great interesting for the researchers. Opioids have been a hot topic for their powerful pain relieving properties and their potential for recreational abuse1,2. In the previous paper3 we have reported the synthesis of 2- substituted hexahydro-1H-1, 4-diazepine analogues. In order to get more selective k-opioid receptor agonists, which can elicit ana lgesia while lacking serious side effects, a series of 5-substituted hexahydro-1H-1, 4-diazepine analo…     

Stereospecific intramolecular C-H amination of 1-aza-2-azoniaallene salts

We report that 1-aza-2-azoniaallene salts, generated from α-chloroazo compounds by treatment with halophilic Lewis acids, participate in intramolecular C-H amination reactions to provide pyrazoline products in good to excellent yield. This intramolecular amination occurs readily at both benzylic and tertiary aliphatic positions and proceeds at an enantioenriched chiral center without loss of enantiomeric excess. A competition reaction shows that insertion occurs more readily at an electron-rich benzylic position than an electron-deficient one. These observations are consistent with the 1-aza-2-azoniaallene intermediate reacting as a nitrenium-like ion by a concerted insertion mechanism.     

A Stereospecific Synthesis of Biotin from an Aromatic Precursor. Preliminary Communication

The total synthesis of the important natural product biotin 1 from the readily available keto diester 3 is described. This approach features the stereospecific hydrogenation of the thiophene intermediate 19 as the key synthetic step. The required differentiation of the diacid functionality of compound 7 is achieved by selective lactam formation with the terminal acid to yield the 8-membered lactam 8 . A modified Curtius reaction then affords the rearranged diurethane 18 through a series of acyl transfers. Finally, a novel conversion of the 3, 4-diurethane moiety to the imidazolidone portion of biotin is utilized to complete the synthesis.     

1,2-Benzothiazines VIII. A novel semmler-wolff type transformation of 2-methyl-2H-1,2-benzothiazin-4-one 1,1-dioxide oxime

Refluxing the oxime ( 1 ) of 2-methyl-2H-1,2-benzothiazin-4(3H)one 1,1-dioxide with tri-fluoroacetic acid or with boron trifluoride in acetic acid gives the corresponding N-acyl derivative ( 2 or 3) of 4-amino-2-methyl-2H-1,2-benzothiazin-3(4H)one 1,1-dioxide. This transformation appears to be related to the acid catalyzed conversion of α-tetralone oxime to α-naphthylamine.     

A new diene, 2-methoxy-1,3-pentadiene-5-ol. Synthesis and intramolecular diels-alder reactions

Reactions of the diene 1-benzyloxy-2-methoxy-1,3-pentadiene-5-ol in intramolecular Diels-Alder reactions using maleic anhydride or fumaric acid ethyl ester is described. The new reactive diene is prepared starting from 3-methoxypyridine. The structure of the diene was elucidated by a NOE nmr experiment.     

A Stereospecific Synthesis of Cis-3-Substituted-2, 2-Dimethylcyclopropane-L-Carboxylates

A stereospecific synthesis of cis-3-substituted-2, 2-dimethylcyclopropane-1-carboxylates based on the cyclization of 5-bromolactone 2 to give bicyclic lactone 3 is described.     

Synthesis of 1,2-diheteroatom-substituted alkenes via rhodium-catalyzed intramolecular hydrogen transfer

While 1,2-diheteroatom-substituted alkenes represent useful synthetic building blocks, there are no simple, general procedures available for preparation of such compounds. We describe here a simple catalytic procedure based on rhodium C-H bond activation for the synthesis of diheteroatom alkenes of the type R(3)SiOCH=CHG (G = -OR, -NRR').     

A new electrophilic addition to acetylenes. Synthesis of 1,2-iodofunctionalized olefins

Acetylenes react with bis(pyridine)iodo(I) tetrafluoroborate (1) in the presence of a wide variety of nucleophiles (F, Cl, Br, I, SCN, pyridine, OAc, anisole, H) to give 1,2-iodofunctionalized olefins (4).     

Synthesis of a new siladigermirane via an intramolecular reductive cyclization

Si,Si-diphenyltetramesitylsiladigermirane was synthesized via the intramolecular reductive cyclization of bis(chlorodimesitylgermyl)diphenylsilane using t-BuLi or Rieke magnesium. Addition of water to the siladigermirane resulted in regioselective hydrolysis of the siladigermirane to give 1-(hydroxydiphenylsilyl)-1,1,2,2-tetramesityldigermane.     

Stereospecific Bromine Replacement in the Synthesis of 4(e) and 4(a)-Deuterioadamantan-2-ones

Stereospecific introduction of deuterium on the adamantane skeleton has been accomplished with LiAID(OCH₃)₃-CuI.     

Synthesis and characterization of new aromatic polyesters and polyethers derived from 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethylene

New polyarylates and aromatic polyethers were synthesized from 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethylene, and aromatic dicarboxylic acid chlorides and aromatic dihalides, respectively. The polyarylates having inherent viscosities of 0.28–1.05 dL/g were synthesized by either the two-phase method or the high-temperature solution method. All the polymers were easily soluble in N-methyl-2-pyrrolidone, N,N-dimethylformamide, pyridine, m-cresol, 1,4-dioxane, and 1,1,2,2-tetrachloroethane. They have glass transition temperatures in the range of 217–250°C and showed no weight loss below 315°C in both air and nitrogen atmospheres. Aromatic polyethers with inherent viscosities of 0.85–1.21 dL/g were obtained by the polycondensation of 1,2-bis(4-hydroxyphenyl)-1,2-diphenylethylene and aromatic difluorides in the presence of potassium carbonate. These polymers having glass transion temperatures of 193–220°C were also soluble in the aforementioned solvents and stable up to around 350deg;C in both atmospheres. © 1994 John Wiley & Sons, Inc.     

4H-3,1-benzoxazines. 2. Synthesis of 2,4-substituted 1,2-dihydro-4H-3,1-benzoxazines

The reactions of o-aminophenylcarbinols with carbonyl compounds have been studied. Optimum conditions have been developed for the synthesis of 2-(5-X-2-furyl)-1,2-dihydro-4H-3,1-benzoxazines. It was found that 2,2-disubstituted 1,2-dihydro-4H-3,1-benzoxazines are unstable and are converted upon heating in the presence of acylating agents to 4H-3,1-benzoxazines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 842–847, June, 1988.     

Synthesis of imidazo[1,2-a] pyridinium salts from 2-alkylaminopyridines. A reexamination

1-Alkyl-2-hydroxy-2,3-dihydroimidazo [1,2-a] pyridinium salts (III) have been identified as isolatable intermediates in the synthesis of 1-alkylimidazo[1,2-a] pyridinium salts (II) from 2-alkylaminopyridines and α-haloketones. Spectral data suggest that these intermediates exist exclusively as the cyclic ring tautomers III rather than chain tautomers VI.     

Cycloaddition reactions. A new type of cycloadduct from a substituted 2-vinylthiophen and dmad

Cycloaddition reactions between 2-(1-cyanoallyl)thiophen and the dienophiles diethyl azodicarboxylate, N-phenylmaleimide , methyl propiolate, and dimethyl acetylenedicarboxylate are reported. Products include simple benzo[b] thiophen carboxylates (13,19) and reduced derivatives (8,9,10,12,18), as a mixture of diastereoisomers, except in the adduct with diethyl azodicarboxylate. With dimethyl acetylenedicarboxylate a new type of tricyclic compound was also found (20).