Abstract

An innovative and efficient monoalkylation and nonsymmetrical 3,3-dialkylation of oxindoles has been achieved. First, the monoalkylation of 3-acetyl-2-oxindoles can be performed in good yields under mild reaction conditions using alkyl halides and benzyltrimethylammonium hydroxide (Triton B) as base at room temperature. This methodology is applied to construct the synthetically challenging compound 1,3-dimethyl-2-oxindole. Subsequent deacylative alkylation (DaA) of the alkylated 3-acetyl-2-oxindoles with alkyl halides takes place efficiently using LiOEt or by conjugate addition with electron-deficient alkenes in the presence of Triton B at room temperature under argon, affording the corresponding unsymmetrically 3,3-disubstituted 2-oxindoles. This simple methodology has been applied to the synthesis of precursors of horsfiline, esermethole, physostigmine, and phenserine alkaloids.

An innovative and efficient monoalkylation and nonsymmetrical 3,3-dialkylation of oxindoles has been achieved. First, the monoalkylation of 3-acetyl-2-oxindoles can be performed in good yields under mild reaction conditions using alkyl halides and benzyltrimethylammonium hydroxide (Triton B) as base at room temperature. This methodology is applied to construct the synthetically challenging compound 1,3-dimethyl-2-oxindole. Subsequent deacylative alkylation (DaA) of the alkylated 3-acetyl-2-oxindoles with alkyl halides takes place efficiently using LiOEt or by conjugate addition with electron-deficient alkenes in the presence of Triton B at room temperature under argon, affording the corresponding unsymmetrically 3,3-disubstituted 2-oxindoles. This simple methodology has been applied to the synthesis of precursors of horsfiline, esermethole, physostigmine, and phenserine alkaloids.

中文翻译：

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3-乙酰基-2-氧吲哚的脱酰基烷基化反应合成3,3-二取代的2-Oxindoles

摘要

已经实现了创新和有效的羟吲哚单烷基化和不对称3,3-二烷基化。首先，在室温下，使用烷基卤和苄基三甲基氢氧化铵（Triton B）作为碱，可以在温和的反应条件下以高收率进行3-乙酰基-2-恶吲哚的单烷基化。该方法学被用于构建具有合成挑战性的化合物1,3-二甲基-2-氧吲哚。随后使用LiOEt或在室温下在氩气下在Triton B存在下，在Triton B的存在下，通过与电子不足的烯烃共轭加成，可以有效地进行烷基化3-乙酰基-2-氧吲哚与烷基卤化物的后续脱酰基烷基化（DaA），得到相应的不对称3 ，3-二取代的2-氧吲哚。这种简单的方法已应用于合成霍斯菲林，乙二胺，

已经实现了创新和有效的羟吲哚单烷基化和不对称3,3-二烷基化。首先，在室温下，使用烷基卤和苄基三甲基氢氧化铵（Triton B）作为碱，可以在温和的反应条件下以高收率进行3-乙酰基-2-恶吲哚的单烷基化。该方法学被用于构建具有合成挑战性的化合物1,3-二甲基-2-氧吲哚。随后使用LiOEt或在室温下在氩气下在Triton B存在下，在Triton B的存在下，通过与电子不足的烯烃共轭加成，可以有效地进行烷基化3-乙酰基-2-氧吲哚与烷基卤化物的后续脱酰基烷基化（DaA），得到相应的不对称3 ，3-二取代的2-氧吲哚。这种简单的方法已应用于合成霍斯菲林，乙二胺，