Development of Jacobsen Asymmetric Epoxidation and Sharpless Asymmetric Dihydroxylation Methods for the Large-Scale Preparation of a Chiral Dihydrobenzofuran Epoxide

Prasad, J. Siva; Vu, Truc; Totleben, Michael J.; Crispino, Gerard A.; Kacsur, David J.; Swaminathan, Shankar; Thornton, John E.; Fritz, and Alan; Singh, Ambarish K.

doi:10.1021/op025622e

Cited by 39 publications

(11 citation statements)

References 36 publications

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“…Prasad et al [75] carried out the preparation of chiral dihydrobenzofuran epoxide with microreactor technologies using Jacobsen asymmetric epoxidation and sharpless asymmetric dihydroxylation followed by epoxidation. Bristol- Several other reactions which have been performed using commercially available Cytos ® microreactors (100 × 150 mm in size) are: (i) six-stage synthesis of ciprofl oxacin, (ii) nitration of toluene with highly explosive acetyl nitrate, (iii) nitration of pyridine-n -oxide at high temperature, and (iv) nitration of 2-methylindole.…”

Section: Microreactor Technologymentioning

confidence: 99%

Process intensification in green synthesis

Kumar

Nigam

2012

Green Processing and Synthesis

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In the past few decades there has been an extensive increase in the research for green synthesis processes due to environmental concerns, industrial safety and sustainable development, which makes it an attractive alternative to the conventional synthesis processes. The interest of researchers in the green synthesis processes highlights the importance of understanding the mechanism and the fundamental differences between the different processes. The number of publications in the fi eld of " Green Synthesis " in journals, proceedings, patents, etc. has increased by almost 20 times from 2001 to 2010. The published reports are mainly concerned with green synthesis with catalytic processes, less harmful solvents and process intensifi ed techniques. In the present article, the technological development efforts in the area of green synthesis are summarized. Various techniques for green synthesis process intensifi cation are discussed, e.g., mixers, microreactors, spin disc reactor, oscillated fl ow reactors, microwave irradiation, ultrasonication, multifunctional membranes and coiled fl ow inverter. The applications of green synthesis processes for biofuel, nanoparticle, ionic liquids and pharmaceutical production are also discussed.

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Section: Microreactor Technologymentioning

confidence: 99%

Process intensification in green synthesis

Kumar

Nigam

2012

Green Processing and Synthesis

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“…m- CPBA is a common oxidant that is widely used in the laboratory for heteroatom oxidations and epoxidations . However, the safety concerns with its use on large scale are well-known, with the pure solid being shock-sensitive and potentially explosive in the condensed phase . In our recent project, m- CPBA was used for the transformation of thioether to sulfoxide and sulphone.…”

Section: Introductionmentioning

confidence: 99%

Safer Preparation of m-CPBA/DMF Solution in Pilot Plant

Zhang

Pan

et al. 2013

Org. Process Res. Dev.

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The usage of m-CPBA (meta-chloroperbenzoic acid) is limited on large scale due to its thermal instability, although it is a good oxidant and well-accepted in laboratory scale. In our recent project, m-CPBA was used for an oxidation reaction, and an explosion hazard was identified. To ensure the safe use of m-CPBA on large scale, the stability of m-CPBA in different solvents was investigated, and it was found that besides the incompatibility between m-CPBA and DMF reported earlier, the intrinsic instability of m-CPBA/DCM solution at high concentration (low onset temperature and large exotherm) can also cause a major problem on large scale. Therefore, process parameters such as concentration of m-CPBA, addition sequence, and handling temperature have been investigated and successfully applied in pilot plant for a large scale reaction using 8 kg of m-CPBA.

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“…[11][12][13][14][15][16][17][18][19] Chromium(salen) complexes have been shown to be capable of mediating a variety of other reactions [20][21][22][23][24][25][26][27][28][29][30][31][32][33] as well as the asymmetric epoxidation (AE) of alkenes. [34][35][36][37] We discovered that the Cr-system shows high enantioselectivity for the conversion of trans-1,2-disubstituted alkenes (trans-alkenes henceforth) in contrast to almost all known Mn(salen) systems.…”

Section: Introductionmentioning

confidence: 99%

Cr-salen mediated asymmetric epoxidation of alkenes: Rational complex design and substrate scope of catalyst

Clarke¹,

McGarrigle²,

Gilheany³

2004

Arkivoc

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Recent explorations of the structure space of Cr(salen) complexes have led to the rational design of improved catalysts for the asymmetric epoxidation of alkenes. The synthesis of these catalysts is presented and their substrate scope detailed.Catalyst 3a, in combination with triphenylphosphine oxide, gives the highest enantiomeric excesses achieved to date in both stoichiometric and catalytic epoxidation with Cr(salen) complexes.

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Development of Jacobsen Asymmetric Epoxidation and Sharpless Asymmetric Dihydroxylation Methods for the Large-Scale Preparation of a Chiral Dihydrobenzofuran Epoxide

Cited by 39 publications

References 36 publications

Process intensification in green synthesis

Process intensification in green synthesis

Safer Preparation of m-CPBA/DMF Solution in Pilot Plant

Cr-salen mediated asymmetric epoxidation of alkenes: Rational complex design and substrate scope of catalyst

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