Solid silica-based sulphonic acid as an efficient green catalyst for the selective oxidation of sulphides to sulphoxides using NaCIO in aqueous media

Solid silica-based sulphonic acid as an efficient green catalyst for the selective oxidation of sulphides to sulphoxides using NaCIO in aqueous media 
Amoozadeh, Ali; Nemati, Firouzeh
S. Afr. J. Chem., 2009, Vol 62, 44-46

http://www.journals.co.za/WebZ/FETCH?sessionid=01-53796-1641319090&recno=2&resultset=1&format=F&next=images/ejour/chem/chem_v62_a10.pdf&bad=ej/ej_badfetch.html&

copy paste  link or go to  http://reference.sabinet.co.za/document/EJC24480

or

https://docs.google.com/viewer?url=http%3A%2F%2Freference.sabinet.co.za%2Fwebx%2Faccess%2Felectronic_journals%2Fchem%2Fchem_v62_a10.pdf

Abstract: A range of sulphides can be selectively oxidized to the corresponding sulphoxides in good yields using NaClO / silica sulphonic acid as an efficient and recyclable solid acid catalyst, in both water and 50 / 50 water / EtOH as solvents. The new method compares favourably with previous methods in the literature.

 

 

ANTHONY MELVIN CRASTO

THANKS AND REGARD’S
DR ANTHONY MELVIN CRASTO Ph.D

MOBILE-+91 9323115463
GLENMARK SCIENTIST , NAVIMUMBAI, INDIA
web link
http://anthonymelvincrasto.brandyourself.com/
http://anthonycrasto.jimdo.com/
http://www.anthonymelvincrasto.yolasite.com/ 

http://www.slidestaxx.com/anthony-melvin-crasto-phd 

http://amcrasto.wix.com/anthony-melvin-crasto/apps/blog
Congratulations! Your presentation titled “Anthony Crasto Glenmark scientist, helping millions with websites” has just crossed MILLION views.
アンソニー     安东尼   Энтони    안토니     أنتوني

NMR INTERPRETATIONS FOR (S)-3-(benzyloxy)-2-methylpropanal

NMR INTERPRETATIONS FOR

(S)-3-(benzyloxy)-2-methylpropanal

VALUES

1H (400 MHz, d Chloroform)

1.15 (3H, d, J 7.0, CH3),

2.63 – 2.72 (1H, m),

3.66 (1H, dd, J 9.5, 5.5),

3.70 (1H, dd, J 9.5, 6.5),

4.54 (2H, s),

7.28-7.39 (5H, m),

9.74 (1H, d, J 1.5)

13C (101 MHz, d Chloroform)

10.7, 46.8, 70.0, 73.3, 127.6, 127.7, 128.4, 137.8, 203.9.

REFERENCES

Zampella, A.; Sorgente, M.; D’Auria, M. V., Tetrahedron: Asymmetry, 2002, 13, 681 – 685  this ref teaches swern oxidn of corresponding alcohol to (S)-3-(benzyloxy)-2-methylpropanal

Harried, S. S.; Lee, C. P.; Yang, G.;Lee, T. I. H.; Myles, D. C., J. Org. Chem., 2003, 68, 6646 – 6660 
Omura, K. ; Sharma, A. K.; Swern, D., J. Org. Chem., 1976, 41, 975 – 962 

other method

SUPP INFO as entry 7 IN

http://www.rsc.org/suppdata/ob/c0/c0ob00491j/c0ob00491j.pdf

Peptide coupling reagents—1-{[1-(Cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethyl­aminomorpholinomethylene]}methaneaminium hexafluo­rophosphate (COMU)

 

Peptide coupling reagents are rapidly evolving in the last years from the classical carbodiimide methods to a second generation onium salts based reactives,[1] and nowadays the novel uronium-type reagents derived from Oxyma like 1-{[1-(Cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethyl­aminomorpholinomethylene]}methaneaminium hexafluo­rophosphate (COMU) introduced by Albericio’s group. This third generation peptide coupling reagent is soluble and stable due to the presence of morpholin. By-products are water-soluble and easy to remove, making COMU an excellent choice as coupling reagent in solid- and liquid-phase peptide synthesis. In addition, COMU shows a less hazardous safety profile than benzotriazole-based reagents like HATU and HBTU, which exhibit unpredictable autocatalytic decomposition and therefore a higher risk of explosion, and cause allergic reactions. COMU gives better results than aza derivatives in the presence of only one equivalent of base, and no activation time is required reducing the common racemization problem. Further, the couplings can be monitored by advantageous visual or colorimetric reaction. Although commercially available, COMU can be prepared easily

Synlett 2012; 23(12): 1849-1850
DOI: 10.1055/s-0031-1290443

https://www.thieme-connect.de/ejournals/html/10.1055/s-0031-1290443

Julián Bergueiro Álvarez

  • Departamento de Química Orgánica, Universidad de Santiago de Compostela,  Spain,

see more on open access paper

https://www.thieme-connect.de/ejournals/html/10.1055/s-0031-1290443

copy paste link

 

Wagner–Meerwein rearrangement

Wagner–Meerwein rearrangement is a class of carbocation 1,2-rearrangement reactions in which a hydrogen, alkyl or aryl group migrates from one carbon to a neighboring carbon. ref1,2

Several reviews have been published.ref 3-7

The rearrangement was first discovered in bicyclic terpenes for example the conversion of isoborneol to camphene ref8:

Isoborneol Camphene Conversion

The story of the rearrangement reveals that many scientists were puzzled with this and related reactions and its close relationship to the discovery of carbocations as intermediates.ref 9

In a simple demonstration reaction of 1,4-dimethoxybenzene with either 2-methyl-2-butanol or 3-methyl-2-butanol in sulfuric acid and acetic acid yields the same disubstituted product,ref 10  the latter via a hydride shift of the cationic intermediate:

Carbocation rearrangement Polito 2010

Currently, there are works relating to the use of skeletal rearrangement in the synthesis of bridged azaheterocycles. These data are summarized in ref11

Some examples of Wagner-Meerwein rearrangement in heterocyclic series

Plausible mechanisms of the Wagner-Meerwein rearrangement of diepoxyisoindoles:

Plausible mechanisms of the Wagner-Meerwein rearrangement of diepoxyisoindoles

The related Nametkin rearrangement named after sergey nametkin involves the rearrangement of methyl groups in certain terpenes. In some cases the reaction type is also called a retropinacol rearrangement 

  1.  Wagner, G. J. Russ. Phys. Chem. Soc. 189931, 690.
  2. Hans Meerwein (1914). “Über den Reaktionsmechanismus der Umwandlung von Borneol in Camphen; [Dritte Mitteilung über Pinakolinumlagerungen.]”. Justus Liebig’s Annalen der Chemie 405: 129–175. doi:10.1002/jlac.19144050202.
  3.  Popp, F. D.; McEwen, W. E. Chem. Rev. 195858, 375. (Review)
  4. Cargill, R. L. et al. Accts. Chem. Res. 19747, 106–113. (Review)
  5. Olah, G. A. Accts. Chem. Res. 19769, 41. (Review)
  6. Hogeveen, H.; Van Krutchten, E. M. G. A. Top. Curr. Chem.197980, 89–124. (Review)
  7. Hanson, J. R. Comp. Org. Syn. 19913, 705–719. (Review)
  8. March, Jerry (1985), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (3rd ed.), New York: Wiley, ISBN 0-471-85472-7
  9. Birladeanu, L. J. Chem. Ed. 200077, 858–863.
  10. Carbocation Rearrangement in an Electrophilic Aromatic Substitution Discovery Laboratory Victoria Polito, Christian S. Hamann and Ian J. Rhile J. Chem. Educ., 2010, 87 (9), pp 969–970 doi:10.1021/ed9000238
  11. Aza-Heterocycles in Wagner–Meerwein Rearrangement: “Skeletal Wagner–Meerwein rearrangement of perhydro-3a,6;4,5-diepoxyisoindoles” Zubkov, F. I. ; Zaytsev, V. P.; Nikitina, E. V.; Khrustalev, V. N.; Gozun, S. V.; Boltukhina, E. V.; Varlamov, A. V. Tetrahedron 2011, 67, 9148-9163 [1]doi:10.1016/j.tet.2011.09.099

Rearrangements- Multiple Wagner-Meerwein shift

NaHSO 4 -SiO 2 as an efficient and chemoselective catalyst, for the synthesis of acylal from aldehydes under, Solvent-free conditions

http://journal.chemistrycentral.com/content/pdf/1752-153X-6-136.pdf

copy paste link on browser

NaHSO 4 -SiO 2 as an efficient and chemoselective catalyst, for the synthesis of acylal from aldehydes under, Solvent-free conditions

Ravi Kumar Kannasani, V V Peruri, Srinivasa Reddy Battula

Chemistry Central Journal 2012, 6:136 (13 November 2012)

Background

Structurally diverse aldehydes are successfully converted into acylals (1,1-diacetates) with acetic anhydride using NaHSO4-SiO2 as a mild, convenient and inexpensive catalyst under solvent-free conditions. The noteworthy features of the present system are shorter reaction times, and mild and solvent-free conditions. Furthermore, it offers chemoselective protection of aldehydes.

Results

Both aromatic and aliphatic aldehydes reacts smoothly with acetic anhydride in presence of silica supported sodium hydrogen sulphate to afford the corresponding 1,1-diacetates in good to excellent yields. We studied competitive reactions for the acylation of aldehydes in the presence of ketones using silica supported sodium hydrogen sulphate as a catalyst. Using this catalytic system, the highly selective conversion of an aldehyde in the presence of ketone was observed

Conclusions

NaHSO4-SiO2 is a chemoselective and highly efficient catalyst for acylal formation from aldehydes. The advantages of this methodology over the reported methods is the availability of the starting materials, simplicity of acylation procedure, a clean work-up, a short reaction time, high yields and reusability.

SERTRALINE

Sertraline hydrochloride (trade names Zoloft and Lustral, among others) is an antidepressant of the selective serotonin reuptake inhibitor (SSRI) class. It was discovered by Pfizer. Sertraline is primarily used to treat major depression in adult outpatients as well as obsessive–compulsive, panic, and social anxiety disorders in both adults and children

Sertraline

Schematic Representation for Synthesis of Sertraline

Conditions:-

i. Benzene, anhydrous aluminum chloride, dichloromethane,

ii. Diethyl succinate, potassium-t-butoxide, t-butyl alcohol, reflux, 16 h,

iii. 48% aqueous HBr, acetic acid, reflux, 36 h,

iv. Hydrogen gas (1 atm), 5% Pd/c catalyst, ethyl acetate, room temperature, 24 h,

v. a) Thionyl chloride, toluene, reflux, 75 min b) anhydrous aluminum chloride, carbon disulfide, room temperature, 16 h,

vi. Methylamine, tetrahydrofuran, titanium tetrachloride, room temperature, 17 h,

vii. a) Hydrogen gas (1 atm), 10% Pd/c catalyst, tetrahydrofuran, room temperature, 2 h b) Gaseous hydrogen chloride,

viii. Crystallization from methanol and ether,

ix) a) 20% sodium hydroxide, ethyl acetate b) D (-) Mandelic acid, ethanol, resolution

Sertraline

CAS No:- [79617-96-2]

IUPAC Name:- (1S,4S)-4-(3,4-Dichlorophenyl)-1,2,3,4-tetrahydro-N-methyl-1-naphthalenamine

MW: 306.23

Drug information:- Sertraline is an anti-depressant drug.

ANTHONY MELVIN CRASTO

DR ANTHONY MELVIN CRASTO Ph.D

MOBILE-+91 9323115463
GLENMARK SCIENTIST , NAVIMUMBAI, INDIA
web link
http://anthonycrasto.jimdo.com/
http://www.anthonymelvincrasto.yolasite.com/ 

http://www.slidestaxx.com/anthony-melvin-crasto-phd 

http://amcrasto.wix.com/anthony-melvin-crasto/apps/blog
Congratulations! Your presentation titled “Anthony Crasto Glenmark scientist, helping millions with websites” has just crossed MILLION views.
アンソニー     安东尼   Энтони    안토니     أنتوني

Convenient One-Pot Two-Step Synthesis of 1,3-Thiazoles via Organocatalyzed Epoxidation of Nitroolefins

Shengwei Wei, Katharina M. Weiß, Svetlana B. Tsogoeva*

Department of Chemistry and Pharmacy, Institute of Organic Chemistry 1, University of Erlangen-Nuremberg, Henkestraße 42, 91054 Erlangen, Germany

Synthesis 2012; 44(22): 3441-3446
DOI: 10.1055/s-0031-1291139
practical synthetic procedures

A convenient novel one-pot two-step strategy and its substrate scope for the synthesis of 1,3-thiazole heterocycles via organocatalytic epoxidation of nitroolefins with the TBHP/DBU system, and subsequent reaction of α-nitroepoxides with thioamides is reported.

/preview/synthesis/201222/z0278_ga.gif