RESUMO
Site-selective C(sp3)-H thiolation using thiosulfonates has been achieved using the decatungstate anion as a photocatalyst. Using the protocol, a variety of thiolated compounds were synthesized in good yields. The transformation consists of a cascade of double SH2 reactions, HAT and ArS group transfer, and PCET (proton-coupled electron transfer) of the leaving arylsulfonyl radical to arylsulfinic acid thus allowing the catalyst, W10O324-, to be recovered.
RESUMO
The zinc-catalyzed regioselective hydrothiolation of alkenes with thiols was achieved in the presence of 4-toluenesulfonic acid. Through this procedure, Markovnikov-type sulfides were synthesized in excellent yields, and the formation of anti-Markovnikov-type sulfides was suppressed. Furthermore, the combination of numerous aryl alkenes with arenethiols or alkyl thiols was achieved using the procedure.
RESUMO
Nickel-catalyzed hydroxysulfonylation of alkenes was achieved using sodium sulfinates under air atmosphere. The procedure enabled the selective synthesis of ß-hydroxysulfones in good yields and suppressed the formation of ß-ketosulfones. On the contrary, sulfonylation of alkynes with sodium sulfonates afforded only ß-ketosulfones.
RESUMO
A copper-catalyzed sulfonylation of disulfides was achieved using sodium sulfinates in air. The reaction formed various sulfur-sulfone bonds efficiently and afforded thiosulfonates in good yields. Selenosulfonates could also be prepared with this procedure. Furthermore, both chalcogenide groups on the dichalcogenides were available in these reactions.
Assuntos
Calcogênios/química , Cobre/química , Selênio/química , Ácidos Sulfínicos/química , Catálise , Dissulfetos/química , Acoplamento OxidativoRESUMO
This article describes the methodology for a copper-catalyzed preparation of numerous monochalcogenides from dichalcogenides with organoboronic acids. Unsymmetrical diorgano-monosulfides, selenides, and tellurides can be synthesized by the coupling of dichalcogenides with aryl- or alkylboronic acids using a copper catalyst in air. The present reaction can take advantage of both organochalcogenide groups on dichalcogenide.
RESUMO
Copper-catalyzed 1,2-hydroxysulfenylation of alkenes can be carried out by the use of disulfides and acetic acid in air. This reaction regio- and anti-selectively gave the corresponding 1,2-acetoxysulfides. Furthermore, the present method enables the use of both organosulfide groups of disulfide.
RESUMO
Various aryl sulfides can be synthesized by nickel-catalyzed alkyl- or arylthiolation of aryl iodide with a disulfide compound. This reaction produces Ni(0) from NiBr2-bpy by the reduction with zinc, and this generated complex works as an activating species to convert ArI into ArSR under neutral conditions. Furthermore, this system enables the use of two RS groups in (RS)2.
RESUMO
The methodology for a copper-catalyzed preparation of diaryl chalcogenide compounds from aryl iodides and diphenyl dichalcogenide molecules is reported. Unsymmetrical diaryl sulfide or diaryl selenide can be synthesized from aryl iodide and PhYYPh (Y = S, Se) with a copper catalyst (CuI or Cu(2)O) and magnesium metal in one pot. This reaction can be carried out under neutral conditions according to an addition of magnesium metal as the reductive reagent. Furthermore, it is efficiently available for two monophenylchalcogenide groups generated from diphenyl dichalcogenide.
RESUMO
Samarium iodide-mediated cross-coupling of N-tosyl ferrocenylideneamine with planar chiral ferrocenecarboxaldehydes or benzaldehyde chromium complexes gave diastereoselectively the corresponding anti-beta-amino alcohol derivatives in good yields, while N-tosyl benzylideneamine produced syn-beta-amino alcohols by coupling with planar chiral arylaldehydes. Dynamic kinetic resolution of a configurationally equilibrated reactive species generated from achiral N-tosyl ferrocenilideneamine and benzylideneamine by reduction with samarium iodide was observed in the cross-coupling with planar chiral arylaldehydes giving both antipodes of beta-amino alcohols depending on the planar chirality. The obtained anti-beta-amino alcohol with the ferrocene ring was utilized as a chiral ligand for catalytic asymmetric reduction of acetophenone.
RESUMO
[reaction: see text] Samarium iodide mediated reductive cross-coupling of N-tosyl benzylideneamine with benzaldehydes or the corresponding chromium complexes gave syn-beta-amino alcohol derivatives. A dynamic kinetic resolution of a configurationally equilibrated reactive species occurred in the cross-coupling with planar chiral benzaldehyde chromium complexes.
Assuntos
Amino Álcoois/síntese química , Aminas/química , Benzaldeídos/química , Compostos de Benzilideno/química , Reagentes de Ligações Cruzadas/química , EstereoisomerismoRESUMO
Without any formation of stereoisomers, the intramolecular pinacol cyclization of 1-planar chiral mono-Cr(CO)3 complexes of 1,1'-biphenyls with carbonyl functionalities at the 2- and 2'-positions-with samarium diiodide gives cyclic trans-1,2-diols 2. Upon exposure to sunlight, the chromium-complexed diols 2 produce optically pure chromium-free trans-diols 3. Similarly, the corresponding enantiomerically pure trans-1,2-diamines and amino alcohols are obtained from the planar chiral chromium complexes of biphenyls with diimino or keto-imino functionalities. R1 =H, OMe; R2 =H, Me; R3 =H, Me.