Heterocyclic Building Blocks-Isothiazole

Hynninen, Paavo H.; Leppaekases, Tuomo S.; Mesilaakso, Markku published the artcile< The enolate anions of chlorophylls a and b as ambident nucleophiles in oxidations with (-)- or (+)-(10-camphorsulfonyl)oxaziridine. Synthesis of 132(S/R)-hydroxychlorophylls a and b>, Application In Synthesis of 104322-63-6, the main research area is chlorophyll enolate stereoselective hydroxylation camphorsulfonyloxaziridine mechanism; ambident nucleophile chlorophyll enolate; hydroxychlorophyll diastereoselective preparation carbon NMR.

The enolate anions of chlorophylls (Chl) are ambident nucleophiles that are of considerable organic chem. interest in relation to the theory of electron delocalization (aromaticity) and charge-transfer in large conjugated π-systems, as well as for their chem. reactivity. Under deaerated conditions, the (-)- and (+)-enantiomers of (10-camphorsulfonyl)oxaziridine (CSOAI) are effective oxidants for the enolate anions of Chl a and Chl b, when 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) serves as a base. The use of these sterically hindered reagents to hydroxylate Chl a and Chl b is described for the first time. The total yield of 132(S/R)-HO-Chl a was 71 and 90% for the oxidations of Chl a with (-)-CSOAI and (+)-CSOAI, resp. Chl b, however, behaved clearly differently from Chl a. The total yield of 132(S/R)-HO-Chl b was 40% in the oxidation with (-)-CSOAI and 60% in the reaction with (+)-CSOAI. A competing side-reaction, which resulted in the 152-Me, 173-phytyl ester of Mg-151(S/R)-unstable rhodin, was found to lower the yields of the desired main products. The formation of the side-products was largely avoided and the yield of 132(S/R)-HO-Chl b was improved by increasing the volume of hexane and using phosphate buffer in the first step of the work-up. With (-)-CSOAI, a 94% diastereomeric excess (de) was achieved for 132(R)-HO-Chl a, whereas the de for 132(R)-HO-Chl b was 66%. With (+)-CSOAI, the de was 10% for 132(R)-HO-Chl a and 8% for 132(R)-HO-Chl b. The results were interpreted in terms of a nucleophilic reaction mechanism, kinetically controlled by steric hindrance, originating on the one hand in the 17-propionate phytyl ester side-chain, protruding over the isocyclic ring E of the Chl enolate ion, and however, in the bulky camphorsulfonyl unit of CSOAI. Possible reasons for the different results from the Chl b oxidations as compared with those of the Chl a oxidations are discussed. Comparison of the differences in the NMR δC-values between 132(S)- and 132(R)-HO-Chl a as well as those between 132(S)- and 132(R)-HO-Chl b, indicated that the change of stereochem. configuration at C-132 induces only slight differences in the δC-values. Of special interest are the δC-values of C-132, which are at ∼91 ppm for the a- and b-series diastereomers. This C is deshielded by ∼25 ppm relative to the C-132 of 132(R)-Chl a (δC = 65.5). Owing to this, 13C NMR spectroscopy is a good method to distinguish the 132-hydroxylated chlorophylls from the intact, naturally occurring chlorophylls.

Tetrahedron published new progress about Hydroxylation, stereoselective. 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, Application In Synthesis of 104322-63-6.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Glahsl, Gudrun; Herrmann, Rudolf published the artcile< (+)-(3-Oxocamphorsulfonyl)oxaziridine as a highly stereoselective reagent for the oxidation of sulfides to chiral sulfoxides>, HPLC of Formula: 104322-63-6, the main research area is stereoselective oxidation sulfide oxocamphorsulfonyloxaziridine; sulfoxide chiral asym synthesis; aldehyde sulfinyl chiral.

The synthesis of the title oxaziridine (I) and its application to the enantio- or diastereoselective oxidation of sulfides to sulfoxides is described. Enantiomeric excesses up to 66% are observed, showing the reagent to be superior to most other oxidizing systems. The exceedingly mild reaction conditions (aprotic, neutral) allow the preparation of several chiral α-sulfinyl aldehydes. The properties. of these compounds are discussed.

Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) published new progress about Stereochemistry. 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, HPLC of Formula: 104322-63-6.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Schultz, Arthur G.; Harrington, Roger E.; Holoboski, Mark A. published the artcile< Asymmetric oxidations of enolates derived from Birch reduction of methyl 2-methoxybenzoate and (S)-2-methoxy-1-[[2'-(methoxymethyl)pyrrolidinyl]carbonyl]benzene>, Electric Literature of 104322-63-6, the main research area is asym oxidation enolate Birch reduction methoxybenzoate.

Asym. oxidation of the ester enolate generated by Birch reduction of Me 2-methoxybenzoate with (+)-2(R,8aS)-(camphorsulfonyl)oxaziridine (I) gave 6-carbomethoxy-1-methoxy-1,4-cyclohexadien-6-ol (II) in 50-60% isolated yields with 30% enantiomeric excess. Double asym. induction via oxidation of the chiral enolate derived from (S)-2-methoxy-1-[[2-(methoxymethyl)pyrrolidinyl)carbonyl]benzene with I gave pyrrolidine III with a diasteriomeric excess as high as 93%.

Journal of Organic Chemistry published new progress about Oxidation, stereoselective. 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, Electric Literature of 104322-63-6.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Cermak, Steven C.; Wiemer, David F. published the artcile< Synthesis of derivatives of (1R)-(-)- and (1S)-(+)-10-camphorsulfonic acid>, Recommanded Product: (4aS,7R,8aS)-9,9-Dimethyltetrahydro-4H-4a,7-methanobenzo[c][1,2]oxazireno[2,3-b]isothiazole 3,3-dioxide, the main research area is laboratory experiment enantiomer camphorsulfonic acid derivative preparation; camphorsulfonate oxaziridine enantiomer laboratory experiment preparation.

A new series of experiments for undergraduate organic chem. laboratory were developed at the University of Iowa, Iowa City, IA, to illustrate concepts of enantiomeric excess and the lack of correlation between absolute configuration and optical rotation. These experiments are based on the preparation of camphorsulfonyloxaziridine derivatives

Journal of Chemical Education published new progress about Absolute configuration. 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, Recommanded Product: (4aS,7R,8aS)-9,9-Dimethyltetrahydro-4H-4a,7-methanobenzo[c][1,2]oxazireno[2,3-b]isothiazole 3,3-dioxide.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Page, Philip C. Bulman; Heer, Jag P.; Bethell, Donald; Collington, Eric W.; Andrews, David M. published the artcile< Asymmetric sulfide oxidation using [(3,3-dimethoxycamphoryl)sulfonyl]oxaziridine>, SDS of cas: 104322-63-6, the main research area is sulfoxide chiral; sulfide enantioselective oxidation dimethoxycamphorylsulfonyloxaziridine.

The system [(3,3-dimethoxycamphoryl)sulfonyl]oxaziridine/H2O2 oxidizes sulfides to sulfoxides cleanly and efficiently in up to 98% ee.

Tetrahedron: Asymmetry published new progress about Oxidation catalysts, stereoselective. 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, SDS of cas: 104322-63-6.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Pienaar, Daniel P.; Khorasani, Sanaz; de Koning, Charles B.; Michael, Joseph P. published the artcile< 3-Hydroxy-1-(4-methoxybenzyl)piperidin-2-one>, Safety of (4aS,7R,8aS)-9,9-Dimethyltetrahydro-4H-4a,7-methanobenzo[c][1,2]oxazireno[2,3-b]isothiazole 3,3-dioxide, the main research area is mol structure hydroxy methoxybenzyl piperidinone; crystal structure hydroxy methoxybenzyl piperidinone; hydrogen bond hydroxymethoxybenzylpiperidinone.

The title compound, C13H17NO3, adopts a conformation in which the aromatic ring and the mean plane of the piperidine ring are almost perpendicular to each other [dihedral angle = 79.25(6)°]. The presence of the carbonyl group alters the conformation of the piperidine ring from a chair to a twisted half-chair conformation. In the crystal, pairs of strong O-H···O H bonds link the mols. into inversion dimers. Weak C-H···O interactions extend the H-bonding network into three dimensions. Crystallog. data and at. coordinates are given.

Acta Crystallographica, Section E: Structure Reports Online published new progress about Crystal structure. 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, Safety of (4aS,7R,8aS)-9,9-Dimethyltetrahydro-4H-4a,7-methanobenzo[c][1,2]oxazireno[2,3-b]isothiazole 3,3-dioxide.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Davis, Franklin A.; Wei, Jia; Sheppard, Aurelia C.; Gubernick, Steven published the artcile< The mechanism of hydroxylation of organometallic reagents by 2-sulfonyloxaziridines>, Computed Properties of 104322-63-6, the main research area is hydroxylation organometallic sulfonyloxaziridine mechanism; phenol octanol cresol.

The hydroxylation of organometallic reagents (e.g. PhMgBr) by 2-sulfonyloxaziridines (e.g. I) is shown to involve a hemiaminal intermediate, whose stability is apparently related to the nucleophilicity of the hydroxylated product (e.g. PhOH).

Tetrahedron Letters published new progress about Grignard reagents Role: RCT (Reactant), RACT (Reactant or Reagent). 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, Computed Properties of 104322-63-6.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Cermak, Diana M.; Du, Yanming; Wiemer, David F. published the artcile< Synthesis of Nonracemic Dimethyl α-(Hydroxyfarnesyl)phosphonates via Oxidation of Dimethyl Farnesylphosphonate with (Camphorsulfonyl)oxaziridines>, Category: isothiazole, the main research area is hydroxyfarnesylphosphonate preparation oxidation camphorsulfonyloxaziridine stereoselective.

Several strategies for synthesis of nonracemic di-Me α-(hydroxyfarnesyl)phosphonate and the parent phosphonic acid have been explored. Separation of diastereomeric derivatives prepared by esterification of racemic α-hydroxy phosphonate with (S)-(+)-O-methylmandelic acid was possible, and these diastereomers could be assigned absolute stereochem. on the basis of literature precedent. However, hydrolysis to the α-hydroxy phosphonic acid was accompanied by extensive isomerization. Addition of a nonracemic phosphonamidite to farnesal also gave nonracemic material, but again hydrolysis was problematic. Oxidation of di-Me farnesylphosphonate anion with nonracemic (camphorsulfonyl)oxaziridines was shown to be regio- and stereoselective for formation of the α-hydroxy phosphonate. Enantiomeric excess of ∼70% ee was established by conversion of the oxidation products to their (S)-(+)-O-methylmandelate derivatives Although hydrolysis of these Me esters was accompanied by extensive racemization, both enantiomers of α-(hydroxyfarnesyl)phosphonic acid were obtained in low ee by this strategy.

Journal of Organic Chemistry published new progress about Selective oxidation (regio- and stereoselective). 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, Category: isothiazole.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Davis, Franklin A.; Kumar, Anil; Reddy, Rajarathnam E.; Chen, Bang Chi; Wade, Peter A.; Shah, Sharmila W. published the artcile< Hydroxylation of dihydroisoxazoles using N-sulfonyloxaziridines>, Electric Literature of 104322-63-6, the main research area is hydroxylation dihydroisoxazole sulfonyloxaziridine; isoxazole dihydro hydroxylation; stereoselective hydroxylation dihydroisoxazole; oxaziridine sulfonyl hydroxylation.

Enantiomerically enriched 4-isoxazolols I (R = Ph, PhS, PhSO2, PhO, R1 = H; R = Ph, R1 = Bu) (26-71% ee) with predictable absolute configuration are available in good yield by hydroxylation of the aza-enolates of 4,5-dihydroisoxazoles (DHI’s) II with (camphorsulfonyl)oxaziridines III (X = H, Cl, MeO). This method is recommended over other oxidation procedures for the preparation of I because of its efficiency, ability to produce chiral products and the avoidance of toxic HMPA.

Journal of Organic Chemistry published new progress about Hydroxylation, stereoselective. 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, Electric Literature of 104322-63-6.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com

Bunnage, Mark E.; Chernega, Alexander N.; Davies, Stephen G.; Goodwin, Christopher J. published the artcile< Asymmetric synthesis of β-amino-α-hydroxy acids via diastereoselective hydroxylation of homochiral β-amino enolates>, Formula: C10H15NO3S, the main research area is amino hydroxy acid stereoselective preparation; alkenoate conjugate addition amine; enolate amino preparation stereoselective hydroxylation.

The highly diastereoselective conjugate addition of lithium N-benzyl-N-α-methylbenzylamide with enoate acceptors, and the electrophilic hydroxylation of the resultant β-amino enolates with (camphorsulfonyl)oxaziridine, is identified as a direct and general strategy for the asym. synthesis of homochiral β-amino-α-hydroxy acids and their derivatives A structurally diverse array of β-amino enolate substrates can be hydroxylated with generally excellent anti diastereoselectivity (>90% d.e.) using this protocol; an alternative stepwise hydroxylation procedure, where the β-amino enolate is prepared by enolization of the preformed conjugate adduct also led to the anti diastereoisomer. The diastereofacial selectivity of enolate hydroxylation appears to be under predominantly substrate-controlled asym. induction, although a measurable degree of chirality recognition with the oxaziridine reagent can be observed Homochiral β-amino-α-keto esters are also prepared and their stereoselective reductions examined

Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) published new progress about Amino acids, hydroxy Role: SPN (Synthetic Preparation), PREP (Preparation). 104322-63-6 belongs to class isothiazole, and the molecular formula is C10H15NO3S, Formula: C10H15NO3S.

Referemce:
Isothiazole – Wikipedia,
Isothiazole – ScienceDirect.com