- Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Formation of Chiral β-Lactams
-
Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates because of their extreme strain and kinetic instability. Reported here is the enantioselective synthesis of 1-sulfonylcyclopropanols, as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, by α-hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as the electrophilic oxygen source. This work constitutes the first general approach to enantioenriched cyclopropanone derivatives. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base-labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines, leading to the efficient formation of chiral β-lactam derivatives.
- Jang, Yujin,Johnson, J. Drake,Jung, Myunggi,Lindsay, Vincent N. G.,Poteat, Christopher M.,Williams, Rachel G.
-
supporting information
p. 18655 - 18661
(2020/08/21)
-
- Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]tri-azolo[1,5-d][1,4]diazepine derivatives by [3+ + 2]-cyclo-addition/rearrangement reactions
-
Two new series of tricyclic heterocycles, namely 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepinium salts 10 and the related neutral, free bases 13 were synthesized from 4-acetoxy-1-acetyl-4-phenylazo-1,2,3,4-tetrahydroquinolines 8 and nitriles 9 in the presence of aluminium chloride by the [3+ + 2]-cycloaddition reaction of the in situ generated azocarbenium intermediates 14 followed by a ring-expansion rearrangement. In the rearrangement reaction, the phenyl substituent in the initially formed spiro-triazolium adducts 16 underwent a [1,2]-migration from C(3) to the electron-deficient N(2). This led to the ring expansion from 6-membered piperidine to 7-membered diazepine furnishing the tricyclic 1,2,4-triazole-fused 1,4-benzodiazepines.
- Luan, Lin-bo,Song, Zi-jie,Li, Zhi-ming,Wang, Quan-rui
-
supporting information
p. 1826 - 1833
(2018/08/21)
-
- Asymmetric Synthesis of Cyclopentene-Fused Tetrahydroquinolines via N-Heterocyclic Carbene Catalyzed Domino Reactions
-
A new strategy for the N-heterocyclic carbene catalyzed asymmetric synthesis of cyclopentene-fused tetrahydroquinoline derivatives has been developed. The one-pot organocatalytic domino protocol allows a direct entry to the characteristic cyclopenta[ c ]tetrahydroquinoline core of many alkaloids and some potential drugs employing readily available quinolinone and enal substrates in good domino yields and stereoselectivities.
- Zhao, Long,Li, Sun,Wang, Lei,Yu, Shun,Raabe, Gerhard,Enders, Dieter
-
p. 2523 - 2532
(2018/05/28)
-
- Ruthenium-Pincer-Catalyzed Hydrogenation of Lactams to Amino Alcohols
-
By using the commercially available ruthenium pincer complex (Ru-MACHO-BH) as a catalyst, the challenging direct hydrogenation of lactams and analogues has been successfully accomplished to deliver corresponding value-added amino alcohols in good-to-excellent yields under mild reaction conditions. Remarkably, in addition to N-protected lactams, unprotected ones could also be readily reduced in the presence of a catalytic amount of weak base or even under neutral reaction conditions, which further highlights the broad substrate scope and the protocol efficiency.
- Chen, Jiangbo,Wang, Jiaquan,Tu, Tao
-
p. 2559 - 2565
(2018/07/30)
-
- Formation of acridones by ethylene extrusion in the reaction of arynes with β-lactams and dihydroquinolinones
-
N-Unsubstituted β-lactams react with a molecule of aryne by insertion into the amide bond to form a 2,3-dihydroquinolin-4-one, which subsequently reacts with another molecule of aryne to form an acridone by extrusion of a molecule of ethylene. 2,3-Dihydroquinolin-4-ones react under the same reaction conditions to afford identical results. This is the first example of ethylene extrusion in aryne chemistry.
- Fang, Yuesi,Rogness, Donald C.,Larock, Richard C.,Shi, Feng
-
experimental part
p. 6262 - 6270
(2012/09/22)
-
- Chroman and tetrahydroquinoline ureas as potent TRPV1 antagonists
-
Novel chroman and tetrahydroquinoline ureas were synthesized and evaluated for their activity as TRPV1 antagonists. It was found that aryl substituents on the 7- or 8-position of both bicyclic scaffolds imparted the best in vitro potency at TRPV1. The most potent chroman ureas were assessed in chronic and acute pain models, and compounds with the ability to cross the blood-brain barrier were shown to be highly efficacious. The tetrahydroquinoline ureas were found to be potent CYP3A4 inhibitors, but replacement of bulky substituents at the nitrogen atom of the tetrahydroisoquinoline moiety with small groups such as methyl can minimize the inhibition.
- Schmidt, Robert G.,Bayburt, Erol K.,Latshaw, Steven P.,Koenig, John R.,Daanen, Jerome F.,McDonald, Heath A.,Bianchi, Bruce R.,Zhong, Chengmin,Joshi, Shailen,Honore, Prisca,Marsh, Kennan C.,Lee, Chih-Hung,Faltynek, Connie R.,Gomtsyan, Arthur
-
scheme or table
p. 1338 - 1341
(2011/04/23)
-
- Catalytic hydrogenation of carboxamides and esters by well-defined Cp*Ru complexes bearing a protic amine ligand
-
A novel catalytic method for the straightforward hydrogenation of carboxamides and esters to primary alcohols has been developed. Chiral modification in the ligand sphere of the well-defined Cp*Ru catalyst molecule opens up a new possibility for the development of an enantioselective hydrogenation of racemic substrates via dynamic kinetic resolution.
- Ito, Masato,Ootsuka, Takashi,Watari, Ryo,Shiibashi, Akira,Himizu, Akio,Ikariya, Takao
-
supporting information; body text
p. 4240 - 4242
(2011/06/21)
-
- Synthesis of 2,3-dihydro-4(1H)-quinolones and the corresponding 4(1H)-quinolones via low-temperature fries rearrangement of N-arylazetidin-2- ones
-
N-Arylazetidin-2-ones of the general form 1, which are readily prepared by GoldbergBuchwald-type copper-catalyzed coupling of N-unsubstituted azetidin-2-ones with the relevant aryl halide or using Mitsunobu cyclization processes, undergo smooth Fries-rearrangement in triflic acid at 018°C to give the isomeric 2,3-dihydro-4(1H)-quinolones (2). Dehydrogenation of the latter compounds using 10% Pd on C in 1.0M aqueous sodium hydroxide/propan-2-ol mixtures at ca. 82°C provides the corresponding 4(1H)-quinolones (3).
- Lange, Jens,Bissember, Alex C.,Banwell, Martin G.,Cade, Ian A.
-
experimental part
p. 454 - 470
(2011/10/09)
-
- Efficient and regioselective synthesis of 5-hydroxy-2-isoxazolines: Versatile synthons for isoxazoles, β-lactams, and γ-amino alcohols
-
"Chemical Equation Presented" An efficient and highly regioselective protocol was developed for the preparation of 5-hydroxy2-isoxazolines, which have been proved to be versatile synthons for isoxazles, β-hydroxy oximes, and γ-amino alcohols. β-Lactams, commonly embedded in the skeletons of bioactive natural products, were also synthesized in two steps from β-hydroxy oximes, providing a new strategy for the synthesis of this kind of compounds.
- Tang, Shibing,He, Jinmei,Sun, Yongquan,He, Liuer,She, Xuegong
-
supporting information; experimental part
p. 1961 - 1966
(2010/06/20)
-
- USE OF 2-IMIDAZOLES FOR THE TREATMENT OF CNS DISORDERS
-
The present invention relates to the use of compounds of formula (I) R1 is hydrogen, tritium, hydroxy, lower alkyl, lower alkoxy, halogen, nitro, amino or lower alkyl substituted by halogen; R2 is hydrogen, hydroxy or lower alkyl; X is N and Y is CH or CH2 or CH-lower alkyl or X is CH and Y is N; Q is CH2, O, NH, N-alkyl or N-SO2-alkyl or N-SO2-toluen-4-yl; W is CH2 or a bond are independently from one another 1, 2 or 3; when m is 2 or 3, R2 may m, n be the same or not; when n is 2 or 3, R1 may be the same or not; the dotted lines may each be independently from one another a bond or not; and to their pharmaceutically active salts, racemic mixtures, enantiomers, optical isomers and tautomeric forms of compounds of formula (I) for the preparation of medicaments for the treatment of depression, anxiety disorders, bipolar disorder, attention deficit hyperactivity disorder, stress-related disorders, psychotic disorders such as schizophrenia, neurological diseases such as Parkinson's disease, neurodegenerative disorders such as Alzheimer's disease, epilepsy, migraine, hypertension, substance abuse and metabolic disorders such as eating disorders, diabetes, diabetic complications, obesity, dyslipidemia, disorders of energy consumption and assimilation, disorders and malfunction of body temperature homeostasis, disorders of sleep and circadian rhythm, and cardiovascular disorders.
- -
-
Page/Page column 47-48
(2010/11/28)
-
- Pd-catalyzed intermolecular amidation of aryl halides: The discovery that xantphos can be trans-chelating in a palladium complex
-
A general method for the intermolecular coupling of aryl halides and amides using a Xantphos/ Pd catalyst is described. This system displays good functional group compatibility, and the desired C-N bond forming process proceeds in good to excellent yields with 1-4 mol % of the Pd catalyst. Additionally, the arylation of sulfonamides, oxazolidinones, and ureas is reported. The efficiency of these transformations was found to be highly dependent on reaction concentrations and catalyst loadings. A Pd complex resulting from oxidative addition of 4-bromobenzonitrile, (Xantphos)Pd(4-cyanophenyl)(Br) (II), was prepared in one step from Xantphos, Pd2(dba)3, and the aryl bromide. Complex II proved to be an active catalyst for the coupling between 4-bromobenzonitrile and benzamide. X-ray crystallographic analysis of II revealed a rare trans-chelating bisphosphine-Pd(II) structure with a large bite angle of 150.7°.
- Yin, Jingjun,Buchwald, Stephen L.
-
p. 6043 - 6048
(2007/10/03)
-
- Copper-promoted C-N bond cross-coupling with phenylstannane
-
Copper-promoted C-N bond cross-coupling of NH-containing substrates with phenylstannane at room temperature was accomplished with the addition of TBAF.
- Lam, Patrick Y.S.,Vincent, Guillaume,Bonne, Damien,Clark, Charles G.
-
p. 3091 - 3094
(2007/10/03)
-
- Copper-catalyzed N-arylation of amines with hypervalent iodonium salts
-
The copper-catalyzed N-arylation of amines with hypervalent iodonium compounds with secondary aliphatic amines, aromatic amines, azoles and amides was accomplished with catalytic CuI (10 mol%) or Cu(acac)2 (5 mol%) in the presence of Na2CO3 or K2CO3 as a base in CH2Cl2 or toluene under mild conditions.
- Kang, Suk-Ku,Lee, Sang-Ho,Lee, Duckhee
-
p. 1022 - 1024
(2007/10/03)
-
- A new synthesis of N-phenyl lactams
-
The synthesis of N-phenyl lactams by phase transfer oxidation of N,N- (polymethylene) anilines with potassium permanganate is reported.
- Markgraf, J. Hodge,Stickney, Carolyn A.
-
p. 109 - 110
(2007/10/03)
-
- Palladium-catalyzed intermolecular coupling of aryl halides and amides
-
The first general intermolecular C-N bond-forming reactions between aryl halides and amides were realized using a palladium catalyst with Xantphos as the ligand. Aryl triflates, carbamates, and sulfonamides are also viable substrates for the amidations, which proceed at 45-110 °C with 1-4 mol% of Pd catalyst in 66-99% yields and exhibit good functional group compatibility.
- Yin, Jingjun,Buchwald, Stephen L.
-
p. 1101 - 1104
(2007/10/03)
-
- Palladium-catalyzed coupling of lactams with bromobenzenes
-
An efficient method for the coupling of lactams with bromobenzenes mediated by palladium acetate and DPPF is presented. The reaction proceeds efficiency with a variety of lactams and both electron-rich and poor substituted bromobenzenes.
- Shakespeare, William C.
-
p. 2035 - 2038
(2007/10/03)
-
- β-Lactams from tetrahydro-1,2-oxazine-3,6-diones, and a labelling study of the product stereochemistry
-
The stereochemistry of the N-C bond-forming step in the photochemical conversion of a tetrahydro-1,2-oxazine-3,6-dione to a β-lactam has been shown to take place with scrambling of stereochemistry using a deuterium labelled precursor.
- Procter, Carry,Nally, James,Ordsmith, Nicholas H. R.
-
p. 12837 - 12842
(2007/10/02)
-
- Acyloxylation at the 4-Position of Azetidin-2-ones
-
The copper-catalysed reaction of azetidin-2-ones with t-butyl perbenzoate or peracetate affords the corresponding 4-benzoyloxy- and acetoxy-substituted β-lactams, respectively.N-Unsubstituted 4-acyloxyazetidinones can be synthesized by dearylation of the N-(4-methoxyphenyl)-substituted products with ceric ammonium nitrate.Acyloxylation of β-lactams that are monosubstituted at C-3 affords predominantly trans-products.
- Easton, Christopher J.,Love, Stephen G.,Wang, Peng
-
p. 277 - 282
(2007/10/02)
-
- Convenient Syntheses of Cyclic Carboxamides from α,β,γ,δ and ε-halocarboxamides under Phase Transfer Conditions
-
Piperazine-2,5-diones (2) were prepared by N-alkylation between two molecules of α-halocarboxamides (1) in the presence of a phase transfer catalyst in yields of 64-88percent. β,γ,δ and ε-Lactams (6,9 and 13) were similarly synthesized by intramolecular N-alkylation of the corresponding halocarboxamides (5, 8 and 12) under phase transfer conditions in 53-99percent yields.Keywords--piperazine-2,5-dione; β-lactam; γ, δ, and ε lactams; bis-β-lactam; phase transfer catalyst; intramolecular N-alkylation
- Okawara, Tadashi,Matsuda, Takashi,Furukawa, Mitsuru
-
p. 1225 - 1233
(2007/10/02)
-
- CONVENIENT SYNTHESES OF PIPERAZINE-2,5-DIONES AND LACTAMS FROM HALOCARBOXAMIDES USING PHASE TRANSFER CATALYSTS
-
Inter- and intramolecular N-alkylation of α-halocarboxamides and dihalocarboxamides in the presence of solid phase transfer catalyst led to the corresponding piperazine-2,5-diones (2) and lactams (4) in the yields of 64-88 and 63-99 percent, respectively.A one-pot synthesis of β-lactams (7) from α-methyl-α,β-dibromopropionyl chloride (5) and α-amino acid using phase transfer catalyst was also successfully achieved.
- Okawara, Tadashi,Noguchi, Yoshihide,Matsuda, Takashi,Furukawa, Mitsuro
-
p. 185 - 188
(2007/10/02)
-
- A Convenient Synthesis of Monocyclic β-Lactams by Means of Solid-Liquid Phase Transfer Reactions
-
The intramolecular N-alkylation of β-bromopropionamides (1) under phase transfer conditions afforded monocyclic N-substituted β-lactams (2) in high yields.In a similar manner, cyclization by N1-C4 bond formation gave 4-benzoyl-2-azet
- Takahata, Hiroki,Ohnishi, Yoshinori,Takehara, Hiroyuki,Tsuritani, Kazuko,Yamazaki, Takao
-
p. 1063 - 1068
(2007/10/02)
-
- A CONVENIENT SYNTHESIS OF MONOCYCLIC β-LACTAMS
-
The intramolecular N-alkylation of β-bromopropionamide (1) under phase transfer conditions gave monocyclic β-lactams (2) in high yields.
- Takahata, Hiroki,Ohnishi, Yoshinori,Yamazaki, Takao
-
p. 467 - 469
(2007/10/02)
-
- Formation of 2,3-Dihydro-4(1H)-quinolones and Related Compounds via Fries-type Acid-catalysed Rearrangement of 1-Arylazetidin-2-ones
-
A variety of 1-arylazetidin-2-ones were treated with trifluoroacetic acid under reflux, methanesulphonic acid at 100 deg C, or conc. sulphuric acid to give the corresponding 2,3-dihydro-4(1H)-quinolones via acyl migration and N-CO fission.In the case of 1-(3-substituted phenyl)azetidin-2-ones, two positional isomeric products, 5- and 7-substituted 2,3-dihydro-4(1H)-quinolones were obtained. 4-Methyl, 4-ethoxycarbonyl, and 4-piperidin-2-yl-1-arylazetidin-2-ones and their analogues were also converted into the corresponding 2-substituted 2,3-dihydro-4(1H)-quinolones under acidic conditions.The 3-substituted 1-phenylazetidin-2-ones (36) and (37) were converted into the furoquinoline systems (38) and (40), respectively, by application of this method.
- Kano, Shinzo,Ebata, Tsutomu,Shibuya, Shiroshi
-
p. 2105 - 2111
(2007/10/02)
-