A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

• Xiao Huang,
• Li Yang,
• Rikard Emanuelsson,
• Jonas Bergquist,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 2682–2688, doi:10.3762/bjoc.12.265

• an sp3 carbon increased the yield of the transetherification reaction significantly. Attempts were also made to attach an alkyne to EDOT via the reaction between hydroxymethyl EDOT and propargyl tosylate using DABCO as catalyst, but it led to a very low yield and this EDOT-propargyl product was very

An economical and safe procedure to synthesize 2-hydroxy-4-pentynoic acid: A precursor towards ‘clickable’ biodegradable polylactide

• Quanxuan Zhang,
• Hong Ren and
• Gregory L. Baker

Beilstein J. Org. Chem. 2014, 10, 1365–1371, doi:10.3762/bjoc.10.139

• synthetic route to prepare 1 using cheap and commercially available diethyl 2-acetamidomalonate (4) and propargyl alcohol. The desired product 1 was obtained via alkylation of malonate 4 with propargyl tosylate followed by a one-pot four-step sequence of hydrolysis, decarboxylation, diazotization and

• hydroxylation of propargylic malonate 5 without work-up of any intermediate. Keywords: alkylation; ‘click’ chemistry; ‘clickable’ polylactide; decomposition; diethyl 2-acetamidomalonate; 2-hydroxy-4-pentynoic acid; one-pot; optimization; propargyl bromide; propargyl tosylate; safe and economical; Introduction

• source of acetylene building moiety; and 2) basic reaction conditions involving a low pKa (<24) to avoid the interruption of the ethynyl proton (pKa ~24) while introducing the acetylene moiety. Propargyl tosylate, prepared from propargyl alcohol and tosyl chloride, is a safe analogue of propargyl bromide

An approach towards azafuranomycin analogs by gold-catalyzed cycloisomerization of allenes: synthesis of (αS,2R)-(2,5-dihydro-1H-pyrrol-2-yl)glycine

• Jörg Erdsack and
• Norbert Krause

Beilstein J. Org. Chem. 2013, 9, 1936–1942, doi:10.3762/bjoc.9.229

• allene synthesis by copper-mediated SN2’-substitution [51] (Table 1, see below). In order to establish suitable reaction conditions, we first examined the synthesis of the butyl-substituted model substrate 6a. Treatment of propargyl tosylate 5a with the organocopper reagent formed in situ from n-BuMgCl

• and 9). After these successful model studies, we introduced substituents into the allene which can be removed at a later stage. Treatment of propargyl tosylate 5a with lithium dibromocuprate [57][58][59] or the silylcuprate (PhMe2Si)2CuCNLi2 [60][61] afforded the allenes 6b and 6c with 68 and 77