Preparation of optically active bicyclodihydrosiloles by a radical cascade reaction

• Koichiro Miyazaki,
• Yu Yamane,
• Ryuichiro Yo,
• Hidemitsu Uno and
• Akio Kamimura

Beilstein J. Org. Chem. 2013, 9, 1326–1332, doi:10.3762/bjoc.9.149

• reaction, radical addition–cyclization cascade followed by intramolecular radical substitution (SHi) occurred in one-pot to give optically active bicyclostannolanes in good yields [15]. We are interested in whether such a cascade SHi process might occur with other radical species. We have found that a

Metal-free aerobic oxidations mediated by N-hydroxyphthalimide. A concise review

• Lucio Melone and
• Carlo Punta

Beilstein J. Org. Chem. 2013, 9, 1296–1310, doi:10.3762/bjoc.9.146

• selective oxidation of organic substrates. Radical addition of aldehydes and analogues to alkenes. NHPI/AIBN-promoted aerobic oxidation of 2,6-diisopropylnaphthalene. NHPI/AIBN-promoted aerobic oxidation of CHB. NMBHA/MeOAMVN promoted aerobic oxidation of PUFA. Alkene dioxygenation by means of N-aryl

Homolytic substitution at phosphorus for C–P bond formation in organic synthesis

• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 1269–1277, doi:10.3762/bjoc.9.143

• literature [19][20][21]. This review deals with two transformations, radical phosphination by addition across unsaturated C–C bonds and substitution of organic halides. Review Radical addition of phosphination agents Stannylphosphines of the type R3Sn–PR’2 are known to undergo radical addition to carbon

• reported that diphenyl(trimethylstannyl)phosphine reacts not only with terminal alkynes but also with internal alkynes and allenes (Scheme 4) [24][25]. It is noteworthy that the regioselectivity of the radical addition to propynamide is opposite to that of the relevant ionic Michael addition. Considering

• , considerable polymerization takes place unless substrates or olefinic products are reasonably inert. Yorimitsu and Oshima reported radical addition of a P–S bond across alkyne by using diphenyl(organosulfanyl)phosphine (Table 4) [35]. The addition proceeds mainly in an anti fashion to afford the adducts

Cascade radical reaction of substrates with a carbon–carbon triple bond as a radical acceptor

• Hideto Miyabe,
• Ryuta Asada and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2013, 9, 1148–1155, doi:10.3762/bjoc.9.128

• hydroxamate ester as a chiral Lewis acid coordination moiety was first shown in an intermolecular reaction involving a radical addition and sequential allylation processes. Next, the effect of hydroxamate ester was studied in the cascade addition–cyclization–trapping reaction of substrates with a carbon

• 2002 that hydroxamic acid derivatives are useful achiral templates in enantioselective Diels–Alder reactions [69][70]. To study the effect of hydroxamate ester as an achiral template in the intermolecular radical reaction, our experiments began with the investigation of cascade radical addition

• substrates and the stereochemistry of cyclization. Substrates for testing the cascade transformation. E/Z-selectivity of 9Aa–Ca. Model for the enantioselective reaction. Effect of hydroxamate ester on intermolecular C–C bond-forming reactions. Cascade radical addition–cyclization–trapping reaction of 5 and

Interplay of ortho- with spiro-cyclisation during iminyl radical closures onto arenes and heteroarenes

• Roy T. McBurney and
• John C. Walton

Beilstein J. Org. Chem. 2013, 9, 1083–1092, doi:10.3762/bjoc.9.120

• system necessarily occurs. The most commonly encountered type is C-centred radical addition (often an aryl radical) to an aromatic or heteroaromatic ring ortho to the point of attachment of the tether. In Pschorr and related processes re-aromatisation follows with production of phenanthrene-type

Some aspects of radical chemistry in the assembly of complex molecular architectures

• Béatrice Quiclet-Sire and
• Samir Z. Zard

Beilstein J. Org. Chem. 2013, 9, 557–576, doi:10.3762/bjoc.9.61

• tedious by more traditional routes. The possibility of iterating the radical addition allows for a convergent and highly modular assembly of complex scaffolds. The three successive additions outlined in Scheme 8 and leading to 37 illustrate nicely this approach [25]. One xanthate, 36, and three different

• strategy for creating complexity from simple starting materials. In this approach, the radical sequence brings together the functional groups necessary for the ionic transformation. One example is the sequence that follows the radical addition of xanthate 61 to an alkene depicted in Scheme 12. Exposure of

• the ready formation of bicyclic compound 72 [33]. The use of a phosphonate-containing alkene allows the assembly of numerous polycyclic structures by combining the radical addition of a ketone-bearing xanthate with an intramolecular Horner–Wadsworth–Emmons condensation. This strategy is highlighted in

Radical zinc-atom-transfer-based carbozincation of haloalkynes with dialkylzincs

• Fabrice Chemla,
• Florian Dulong,
• Franck Ferreira and
• Alejandro Pérez-Luna

Beilstein J. Org. Chem. 2013, 9, 236–245, doi:10.3762/bjoc.9.28

• )enoates bearing pendant haloalkynes would be ideally suited (Scheme 1). On the one hand it would provide a means to control totally the regioselectivity of the radical addition to the haloalkyne, and on the other hand the envisioned zinc atom transfer to an α-halo vinylic radical should be favorable as a

Highly selective synthesis of (E)-alkenyl-(pentafluorosulfanyl)benzenes through Horner–Wadsworth–Emmons reaction

• George Iakobson and
• Petr Beier

Beilstein J. Org. Chem. 2012, 8, 1185–1190, doi:10.3762/bjoc.8.131

• chemical stability, high electronegativity and strong lipophilic character [2][3][4][5][6][7]. The availability of SF5-containing compounds is very limited. Aliphatic SF5-containing compounds are available through free-radical addition of toxic and expensive SF5Cl to unsaturated compounds [8][9], and

Tandem catalysis of ring-closing metathesis/atom transfer radical reactions with homobimetallic ruthenium–arene complexes

• Yannick Borguet,
• Xavier Sauvage,
• Guillermo Zaragoza,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2010, 6, 1167–1173, doi:10.3762/bjoc.6.133

• compound was first reported in 2005 by Severin et al. who successfully used it as a catalyst for atom transfer radical addition (ATRA) and cyclization (ATRC) reactions [4][5]. In 2007, we further extended its application field to the related process of atom transfer radical polymerization (ATRP) [2

Novel multi-responsive P2VP-block-PNIPAAm block copolymers via nitroxide-mediated radical polymerization

• Cathrin Corten,
• Katja Kretschmer and
• Dirk Kuckling

Beilstein J. Org. Chem. 2010, 6, 756–765, doi:10.3762/bjoc.6.89

• the last few years. This includes nitroxide-mediated radical polymerization (NMRP) [18], atom transfer radical polymerization (ATRP) [19][20] and radical addition fragmentation chain transfer procedures (RAFT) [21][22]. The controlled polymerization of styrene, and analogous monomers such as 2

Controlling hazardous chemicals in microreactors: Synthesis with iodine azide

• Johan C. Brandt and
• Thomas Wirth

Beilstein J. Org. Chem. 2009, 5, No. 30, doi:10.3762/bjoc.5.30

• Discussion The radical addition of azide to aldehydes 1 initially forms acyl azides 2 which directly rearrange in a Curtius rearrangement to the corresponding isocyanates 3. Isocyanates are very reactive themselves and offer a wide range of possible conversions. An excess of azide leads to the formation of

Part 1. Reduction of S-alkyl- thionocarbonates and related compounds in the presence of trialkylboranes/air

• Jean Boivin and
• Van Tai Nguyen

Beilstein J. Org. Chem. 2007, 3, No. 45, doi:10.1186/1860-5397-3-45

• is known to produce radicals at 20°C, or even much lower temperature (-78°C), we thought that trialkylboranes in the presence of dioxygen would be good candidates to trigger the radical addition of α-acyl S-xanthates onto olefins. When testing this hypothesis, we observed that compound 1a (Figure 1