Asymmetric synthesis of tertiary thiols and thioethers

• Jonathan Clayden and
• Paul MacLellan

Beilstein J. Org. Chem. 2011, 7, 582–595, doi:10.3762/bjoc.7.68

• tertiary thiols 57 directly (Scheme 21), with only the electron rich para-methoxyphenyl substituent performing poorly. As with stereospecific nucleophilic displacement, only specific substrates are tolerated in conjugate additions, and further functionality is always required to activate the electrophilic

New amphiphilic glycopolymers by click functionalization of random copolymers – application to the colloidal stabilisation of polymer nanoparticles and their interaction with concanavalin A lectin

• Otman Otman,
• Paul Boullanger,
• Eric Drockenmuller and
• Thierry Hamaide

Beilstein J. Org. Chem. 2010, 6, No. 58, doi:10.3762/bjoc.6.58

• the azido derivative 3 in almost quantitative yield, by nucleophilic displacement of the chlorine atom by azide ion. Deprotection of the latter under Zemplén conditions [17] afforded the expected derivative 4 in quantitative yield (Figure 1). The copolymer backbones, namely the poly(propargyl acrylate

Bis(oxazolines) based on glycopyranosides – steric, configurational and conformational influences on stereoselectivity

• Tobias Minuth and
• Mike M. K. Boysen

Beilstein J. Org. Chem. 2010, 6, No. 23, doi:10.3762/bjoc.6.23

• step however, on switching to L-selectride for the stereoselective reduction [26], the allosamine derived thioglycoside 10 was obtained in good overall yield. For an alternative route, 7 was transformed into the 3-O-triflate 9 and then subjected to nucleophilic displacement with sodium nitrite in the

(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties

• José L. Jiménez Blanco,
• Fernando Ortega-Caballero,
• Carmen Ortiz Mellet and
• José M. García Fernández

Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20

• , Chiara and co-workers have described a novel complementary approach in which the oxazoline ring is generated by SN2 nucleophilic displacement reaction from the β-hydroxyurea 30 via the triflate intermediate 31 (Scheme 3) [65]. A similar methodology was used by the same authors to prepare the trehazolin

Convergent syntheses of Le^X analogues

• An Wang,
• Jenifer Hendel and
• France-Isabelle Auzanneau

Beilstein J. Org. Chem. 2010, 6, No. 17, doi:10.3762/bjoc.6.17

• isolated in excellent yield whether method A or B was followed. Thus, these syntheses of glycoside 14 constitute efficient alternatives to that reported by Nitz et al. in which the starting material was the corresponding anomeric bromide [45]. Nucleophilic displacement of the chlorine atom in glycoside 14

• glycoside 29 was in turn used as a precursor to the 6-azidohexyl, 6-acetylthiohexyl and 6-thiobenzylhexyl trisaccharides 30–32 (Scheme 3). Thus, nucleophilic displacement of the chloride with sodium azide or potassium thioacetate was carried out in DMF at 80 °C and provided the 6-azidohexyl and 6

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

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

• leaving group X free for nucleophilic displacement with the nitrogen of the newly formed pyrroline. The synthesis began by Mitsunobu coupling of phenol 76 with allylic alcohol 77 to give ether 78, which was heated in N,N-dimethylaniline to trigger a Claisen rearrangement (Scheme 22). A sequence of

Synthesis of crispine A analogues via an intramolecular Schmidt reaction

• Ajoy Kapat,
• Ponminor Senthil Kumar and
• Sundarababu Baskaran

Beilstein J. Org. Chem. 2007, 3, No. 49, doi:10.1186/1860-5397-3-49

• as a white crystalline solid. Diol 9 on bromination followed by nucleophilic displacement with NaCN furnished the desired dicyano compound 10. Treatment of dicyanide 10 with thionyl chloride in methanol gave the corresponding diester 11 as a colorless liquid in good yield. Compound 11 was then

Aroylketene dithioacetal chemistry: facile synthesis of 4-aroyl- 3-methylsulfanyl- 2-tosylpyrroles from aroylketene dithioacetals and TosMIC

• H. Surya Prakash Rao and
• S. Sivakumar

Beilstein J. Org. Chem. 2007, 3, No. 31, doi:10.1186/1860-5397-3-31

• . Future works will concentration on desulfuration of the methylsulfanyl group in 3 to generate 3,5-disubstituted pyrroles or oxidation of methylsulfanyl group to methylsulfonyl group followed by nucleophilic displacement to generate pyrroles of structural diversity. Experimental "See the Supporting

Efficient synthesis of 5-substituted 2-aryl- 6-cyanoindolizines via nucleophilic substitution reactions

• Eugene V. Babaev,
• Natalya I. Vasilevich and
• Anna S. Ivushkina

Beilstein J. Org. Chem. 2005, 1, No. 9, doi:10.1186/1860-5397-1-9

• synthesis of previously unknown 5-chloroindolizines and their use as precursors to novel 5-substituted indolizines via nucleophilic displacement reactions. The synthesis of 2-aryl-5-chloro-6-cyano-7-methylindolizines 2 is shown in Scheme 1. 2-Aryl-6-cyano-7-methyl-5-indolizinones 1 a – d were prepared

Synthesis of 2,6-trans- disubstituted 5,6-dihydropyrans from (Z)-1,5-syn-endiols

• Eric M. Flamme and
• William R. Roush

Beilstein J. Org. Chem. 2005, 1, No. 7, doi:10.1186/1860-5397-1-7

• silylation of the allylic alcohol unit followed by mesylate formation and base-promoted nucleophilic displacement. Findings We recently reported a one-pot double allylboration reaction sequence which provides (Z)-1,5-syn-endiols from simple aldehyde starting materials with excellent diastereo- and