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。
Synthesis of 2-oxindoles via 'transition-metal-free' intramolecular dehydrogenative coupling (IDC) of sp<sup>2</sup> C–H and sp<sup>3</sup> C–H bonds
benzylic position has been achieved via a 'transition-metal-free' intramolecular dehydrogenative coupling (IDC). The construction of 2-oxindole moieties was carried out through formation of carbon-carbon bonds using KOt-Bu-catalyzed one pot C-alkylation of beta-N-arylamido esters with alkyl halides followed by a dehydrogenative coupling. Experimental evidences indicated toward a radical-mediated path for
Development of catalytic deacylative alkylations (DaA) of 3-acyl-2-oxindoles: total synthesis of meso-chimonanthine and related alkaloids
作者:Nivesh Kumar、Mrinal Kanti Das、Santanu Ghosh、Alakesh Bisai
DOI:10.1039/c6cc10228j
日期:——
We present an effective deacylative alkylation strategy for the construction of a variety of 2-oxindoles bearing all-carbon quaternary center at the pseudobenzylic position. A wide variety of products with quaternary...
Catalyst-Assisted Selective Vinylation and Methylallylation of a Quaternary Carbon Center Using <i>tert</i>-Butyl Acetate
作者:Nirmala Mohanta、Pragnya Paramita Samal、Akanksha M. Pandey、Shankhajit Mondal、Sailaja Krishnamurty、Boopathy Gnanaprakasam
DOI:10.1021/acs.joc.2c03072
日期:2023.7.21
tert-butyl acetate is presented as a novel synthetic methodology. Moreover, tert-butyl acetate is a nonflammable feed stock and is a readily available source for the in situ production of vinyl substituents, as demonstrated by the vinylationreaction with quaternary hydroxy/methoxy compounds. Moreover, an excellent selectivity for methylallylation over vinylation was obtained with Ni(OTf)2 as a catalyst
A General Protocol toward Oxindoles Bearing C3‐Allylic Quaternary Stereocenter via Domino Reaction: A Concise Synthesis of Heterocycle‐Fused Indoline Alkaloids
efficiently catalytic method toward the synthesis of indolin-2-ones featuring an allylic derived C3-quaternary stereocenter via an intramolecular Heck cyclization/Suzuki coupling of N-substituted-N-(2-bromophenyl)acrylamides and organoboron reagents was successfully developed by using a 1,3-bis(2,6-diisopropylphenyl)acenaphthoimidazol-2-ylidene (AnIPr)-ligated oxazoline palladacycle. It enabled a very broad