Indium-Mediated Allylation and Propargylation of Isatins: A Facile Synthesis of 3-Substituted 3-Hydroxyoxindoles
作者:Vijay Nair、Sindu Ros、C. N. Jayan、S. Viji
DOI:10.1055/s-2003-42428
日期:——
Isatins undergo efficient allylation/propargylation when reacted with allyl/propargyl bromide in the presence of indium and sodium iodide to afford the corresponding 3-substituted 3-hydroxyoxindoles.
Palladium-catalyzed allylation and deacylative allylation of 3-acetyl-2-oxindoles with allylic alcohols
作者:Aitor Ortega-Martínez、Rocco de Lorenzo、José M. Sansano、Carmen Nájera
DOI:10.1016/j.tet.2017.11.041
日期:2018.1
Pd-catalyzed allylation of 3-acetyl-2-oxindoles with allyl alcohol is performed using 3 mol% of Pd(dba)2, rac-BINAP and BINOL phosphoric acid as catalytic mixture. This procedure allows the in situ synthesis of 3-allyl-2-oxindole by adding Triton B to the reaction mixture. The deacylative allylation of 3-acetyl-3-methyl-2-oxindoles with allylicalcohols is carried out with 3 mol% of Pd(OAc)2, dppp and 1.5
使用3 mol%的Pd(dba)2,rac-BINAP和BINOL磷酸作为催化混合物,进行3-乙酰基-2-氧吲哚与烯丙醇的Pd催化烯丙基化反应。该方法允许通过将Triton B加入反应混合物中原位合成3-烯丙基-2-恶吲哚。用3mol%的Pd(OAc)2,dppp和1.5当量进行3-乙酰基-3-甲基-2-氧吲哚与烯丙基醇的脱酰基烯丙基化。LiO t Bu作为碱,以良好的产率提供了相应的3,3-二取代的2-氧吲哚。可以将两种方法结合起来用于制备不对称的3,3-二烯丙基化的2-氧吲哚,例如化合物7。DaA必须在无氧条件下进行,以避免竞争性形成3-烷基-3-羟基-2-吲哚。通过在室温下在空气中用LiOEt对3-烷基化的3-乙酰基-2-氧吲哚进行3-烷基化的3-乙酰基-2-氧吲哚的酰基化反应,可以容易地获得后面的化合物。
Copper(II) Triflate Catalyzed Regioselective and Enantioselective Propargylation of Isatin Derivatives by Using Allenylboronic Acid Pinacol Ester
作者:Naveen Gupta、Rajkumar Tak、Mohd Nazish、Ajay Jakhar、Noor-ul H. Khan、Rukhsana I. Kureshy
DOI:10.1002/ejoc.201701745
日期:2018.3.22
Regioselectivepropargylation of isatins in aqueous media. With this protocol we could achieve propargyl alcohols in high yields with wide substrate scope. The enantioselective version was also explored to yield chiral alcohols with er up to 12:88, which is reported for the first time.
Despite the great advances achieved in the Pauson–Khandreaction and the ever-increasing demand for fluorinated compounds, the use of vinyl fluorides as olefinic counterparts in the above-mentioned transformation had been completely overlooked. Herein, we describe, for the first time, the intramolecular Pauson–Khandreaction of enynes containing a vinyl fluoride moiety.
Metal-free synthesis of dihydrofuran derivatives as anti-vicinal amino alcohol isosteres
作者:Bhargav Gupta Nangunuri、Rajendra P. Shirke、Mi-hyun Kim
DOI:10.1039/d2ob02077g
日期:——
construct spiro-dihydrofuran and amino dihydrofuran scaffolds as anti-vicinal amino alcohol isosteres. Hypervalent iodine (PhI(OAc)(NTs2))-mediated C–H activation of alkynes resulted in two-bond formations with one pi bond cleavage: (i) C(sp2)–N(sp3) and O(sp3)–C(sp2); (ii) C(sp2)–N(sp3) and C(sp3)–C(sp2). The metal-free 5-endo-dig oxidative cyclization provided versatile amino 2,3- and 2,5-dihydrofurans