Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• in 46% overall yield. Interestingly, oxidation with hydrogen peroxide gave predominantly the N-allylic system rather than the vinylic one. This is in accordance with the precedent established by the laboratory of K.B. Sharpless [80][81]. The overall yield from diazo-ester 67 was only 2% and was

The development and evaluation of a continuous flow process for the lipase- mediated oxidation of alkenes

• Charlotte Wiles,
• Marcus J. Hammond and
• Paul Watts

Beilstein J. Org. Chem. 2009, 5, No. 27, doi:10.3762/bjoc.5.27

• lipase B, Novozym® 435, in a preliminary investigation into the development of a continuous flow reactor capable of performing the chemo-enzymatic oxidation of alkenes in high yield and purity, utilising the commercially available oxidant hydrogen peroxide (100 volumes). Initial investigations focussed

• ; hydrogen peroxide; lipase; micro reactor; Novozym® 435; peracids; Introduction In addition to their synthetic value as intermediates in the preparation of diols, alcohols, hydroxyesters and alkenes, epoxides are a key raw material in many industrial processes, finding application in adhesives, polymers

• situ generated peracids derived from formic acid or acetic acid (1)/hydrogen peroxide (2). As H2O2 (2) is itself not sufficiently electrophilic to epoxidise a non-conjugated double bond directly, its use in the formation of a peracid has afforded a route to the epoxidation of alkenes in the presence of

Efficient 1,4-addition of α-substituted fluoro(phenylsulfonyl)methane derivatives to α,β-unsaturated compounds

• G. K. Surya Prakash,
• Xiaoming Zhao,
• Sujith Chacko,
• Fang Wang,
• Habiba Vaghoo and
• George A. Olah

Beilstein J. Org. Chem. 2008, 4, No. 17, doi:10.3762/bjoc.4.17

• . We first began with the preparation of nitro, cyano, ester, or acetyl-substituted (phenylsulfonyl)methanes from the corresponding (phenylthio)methane derivatives, the precursors of α-substituted fluoro(phenylsulfonyl)methane derivatives. Oxidation of (nitromethyl)(phenyl)sulfide with aqueous hydrogen

• peroxide [H2O2, 30% (wt)] was attempted in acetic acid at room temperature. Tuning the conditions by using 4-fold excess of H2O2 afforded 90% yield of (nitromethylsulfonyl)benzene overnight (Table 1, entry 1) [26][27][28]. 2a–c and 2e were prepared in 76–91% yields under the optimized condition and used

The Elbs and Boyland- Sims peroxydisulfate oxidations

• E. J. Behrman

Beilstein J. Org. Chem. 2006, 2, No. 22, doi:10.1186/1860-5397-2-22

• , although they obtained evidence for a peroxide, isolated only phenol (in substantial yield). Heller and Weiler [18] investigated a more stable analog, namely p-nitrophenyl hydroperoxide formed by ipso displacement of a nitro group from p-dinitrobenzene by the hydrogen peroxide anion.p-Nitrophenyl

The vicinal difluoro motif: The synthesis and conformation of erythro- and threo- diastereoisomers of 1,2-difluorodiphenylethanes, 2,3-difluorosuccinic acids and their derivatives

• David O'Hagan,
• Henry S. Rzepa,
• Martin Schüler and
• Alexandra M. Z. Slawin

Beilstein J. Org. Chem. 2006, 2, No. 19, doi:10.1186/1860-5397-2-19

• lead to poor conversions and a complex product mixture. As an alternative strategy ozonolysis in acetic acid, with a hydrogen peroxide work-up was explored [27][28], and this proved successful as illustrated in Scheme 8. For example, reaction of a 4:1 mixture of erythro- and threo- 13 led to the