Non-oxidative, regioselective, and convergent access to densely functionalized oxazoles is realized in a functional-group tolerant manner using alkynyl thioethers. Sulfur-terminated alkynes provide access to reactivity previously requiring strong donor-substituted alkynes such as ynamides. Sulfur does not act in an analogous donor fashion in this gold-catalyzed reaction, thus leading to complem...

A concise and regioselective preparation of 2-heteroarylmethylene decorated N-arylpyrroles is described through a metal-free Mannich/Wittig/hydroamination sequence followed by isomerization of the N-arylpyrrolidine adducts. Furthermore, the C-H regioselective oxidation of these substrates is demonstrated, extending the molecular diversity and versatility of these scaffolds.

treatment of acetyl- 1,4-benzoquinone with isoprene gave the corresponding regioselective adduct (i). rearrangement of the adduct (1) in pyridine and methanol gave 2-acetyl-5, 8-dihydro-6-methyl- 1,4-dihydroxynaphthalene (2). silver oxide oxidation of the rearranged product (2) gave 2-acetyl-5,8-dihydro- 6-methyl- 1,4naphthalenedione (3). regioselective addition of trans-piperylene to this comp...

the magnetically recoverable fe3o4 nanoparticle and the supported brønsted acidic ionic liquid 1-methyl-3-(3-trimethoxysilylpropyl) imidazolium hydrogen sulfate (fe3o4-il-hso4) were synthesized and used as efficient magnetic catalysts for the regioselective thiocyanation of aromatic and heteroaromatic compounds at room temperature in water: ethanol. this procedure provided the target thiocyanat...

Iodine-catalyzed regioselective sulfenylation of imidazo[1,2-a]pyridines via C(sp(2))-H bond functionalization has been achieved using sulfonyl hydrazides as a thiol surrogate. A library of 3-sulfanylimidazopyridines with broad functionalities was synthesized under metal and oxidant-free practical reaction conditions. This methodology is also applicable for the regioselective sulfenylation of i...

an efficient and simple method for the preparation of si-imidazole-hso4 functionalized magnetic fe3o4 nanoparticles (si-im-hso4 mnps) and used as an efficient and reusable magnetic catalysts for the regioselective ring opening of epoxides under green conditions in water. this catalyst was used for the ring opening of epoxide corresponding to the thiocyanohydrins and azidohydrines. compared to t...

In order to extend the applicability of the regioselective enzymatic carboxylation of phenols, the substrate scope of o-benzoic acid (de)carboxylases has been investigated towards complex molecules with an emphasis on flavouring agents and polyphenols possessing antioxidant properties. o-Hydroxycarboxylic acid products were obtained with perfect regioselectivity, in moderate to excellent yields...

Several Zn b-diiminate reagents were developed and used to mediate regioselective O-acylation reactions of therapeutic agents with anhydrides. Various prodrugs were obtained in excellent yield and high regioselectivity, including derivatives of rapamycin and paclitaxel. Furthermore, the application of regioselective acylation was extended to one-pot reactions between therapeutics and carboxylic...

Regioselective lithiation followed by functionalization of 2-(2,4-dihalophenyl)-1,3-dithiane derivatives with different electrophiles was achieved in good to excellent yields. When the title compound is treated with n-butyl lithium, lithiation occurs selectively at the aromatic carbon having less acidic proton despite the presence of thermodynamically more acidic 1,3-dithiane proton in the same...