The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Noritaka Chida - One of the best experts on this subject based on the ideXlab platform.
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Iridium-Catalyzed Reductive Nucleophilic Addition to Secondary Amides.
Organic letters, 2018Co-Authors: Yoshito Takahashi, Takaaki Sato, Risa Yoshii, Noritaka ChidaAbstract:An iridium-catalyzed reductive Nucleophilic Addition to secondary amides is reported. After the iridium-catalyzed reduction, the resulting imines can undergo the Strecker reaction, the Mannich reaction, allylation, and [3 + 2]-cycloAddition. The method shows high chemoselectivity in the presence of other functional groups such as methyl ester.
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Total synthesis of complex alkaloids by Nucleophilic Addition to amides.
Organic & biomolecular chemistry, 2018Co-Authors: Takaaki Sato, Makoto Yoritate, Hayato Tajima, Noritaka ChidaAbstract:Nucleophilic Addition to amides has been recognized as a promising transformation for total synthesis of complex alkaloids. Amides can accept two different organometallic reagents through the Nucleophilic Addition, which enables it to serve as a stable surrogate of multi-substituted amines. However, the Nucleophilic Addition has been overlooked for a long time due to three main reasons: low electrophilicity of amide carbonyls, potential hydrolysis of the reaction intermediate and excess Addition of an organometallic reagent. This mini review focuses on the recent progress of total synthesis of complex alkaloids based on the Nucleophilic Additions to N-alkoxyamides, tertiary amides and secondary amides.
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Iridium-catalyzed chemoselective reductive Nucleophilic Addition to n -methoxyamides
Organic letters, 2015Co-Authors: Minami Nakajima, Takaaki Sato, Noritaka ChidaAbstract:Iridium-catalyzed reductive Nucleophilic Addition to N-methoxyamides is reported. The reaction took place in high yields in the presence of a variety of sensitive functional groups such as esters and nitro groups. Mechanistic studies revealed that the reaction of N-methoxyamides proceeded without equilibrium to an enamine intermediate in contrast to that with tert-amides.
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Chemoselective reductive Nucleophilic Addition to tertiary amides, secondary amides, and N-methoxyamides.
Chemistry (Weinheim an der Bergstrasse Germany), 2014Co-Authors: Minami Nakajima, Kenji Shirokane, Takaaki Sato, Yukiko Oda, Takamasa Wada, Ryo Minamikawa, Noritaka ChidaAbstract:As the complexity of targeted molecules increases in modern organic synthesis, chemoselectivity is recognized as an important factor in the development of new methodologies. Chemoselective Nucleophilic Addition to amide carbonyl centers is a challenge because classical methods require harsh reaction conditions to overcome the poor electrophilicity of the amide carbonyl group. We have successfully developed a reductive Nucleophilic Addition of mild nucleophiles to tertiary amides, secondary amides, and N-methoxyamides that uses the Schwartz reagent [Cp2 ZrHCl]. The reaction took place in a highly chemoselective fashion in the presence of a variety of sensitive functional groups, such as methyl esters, which conventionally require protection prior to Nucleophilic Addition. The reaction will be applicable to the concise synthesis of complex natural alkaloids from readily available amide groups.
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Nucleophilic Addition to N-alkoxyamides.
Organic & biomolecular chemistry, 2014Co-Authors: Takaaki Sato, Noritaka ChidaAbstract:An amide group is one of the most abundant functional groups in organic synthesis. However, Nucleophilic Addition to amide carbonyls has received less attention than their construction due to their high stability. In this Perspective, we describe our recent progress with N-alkoxyamides. Incorporation of an N-alkoxy group as a reactivity control element into the nitrogen atom of an amide successfully overcomes issues inherent to the Nucleophilic Addition. The reaction can introduce two different nucleophiles in a one-pot process, giving a variety of substituted amines. When the Schwartz reagent was used in the first reduction step, high chemoselectivity was observed in the presence of sensitive functional groups such as esters, which resulted in the concise total synthesis of (±)-gephyrotoxin.
Huanfeng Jiang - One of the best experts on this subject based on the ideXlab platform.
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Palladium-Catalyzed Sequential Nucleophilic Addition/Oxidative Annulation of Bromoalkynes with Benzoic Acids To Construct Functionalized Isocoumarins
Organic letters, 2017Co-Authors: Guangbin Jiang, Chuanle Zhu, Huanfeng JiangAbstract:An efficient and robust protocol for the preparation of 3-substituted isocoumarins via palladium-catalyzed Nucleophilic Addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective Nucleophilic Addition and C–H functionalization procedure.
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Palladium-Catalyzed Sequential Nucleophilic Addition/Oxidative Annulation of Bromoalkynes with Benzoic Acids To Construct Functionalized Isocoumarins
2017Co-Authors: Guangbin Jiang, Chuanle Zhu, Huanfeng JiangAbstract:An efficient and robust protocol for the preparation of 3-substituted isocoumarins via palladium-catalyzed Nucleophilic Addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective Nucleophilic Addition and C–H functionalization procedure
Takaaki Sato - One of the best experts on this subject based on the ideXlab platform.
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Iridium-Catalyzed Reductive Nucleophilic Addition to Secondary Amides.
Organic letters, 2018Co-Authors: Yoshito Takahashi, Takaaki Sato, Risa Yoshii, Noritaka ChidaAbstract:An iridium-catalyzed reductive Nucleophilic Addition to secondary amides is reported. After the iridium-catalyzed reduction, the resulting imines can undergo the Strecker reaction, the Mannich reaction, allylation, and [3 + 2]-cycloAddition. The method shows high chemoselectivity in the presence of other functional groups such as methyl ester.
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Total synthesis of complex alkaloids by Nucleophilic Addition to amides.
Organic & biomolecular chemistry, 2018Co-Authors: Takaaki Sato, Makoto Yoritate, Hayato Tajima, Noritaka ChidaAbstract:Nucleophilic Addition to amides has been recognized as a promising transformation for total synthesis of complex alkaloids. Amides can accept two different organometallic reagents through the Nucleophilic Addition, which enables it to serve as a stable surrogate of multi-substituted amines. However, the Nucleophilic Addition has been overlooked for a long time due to three main reasons: low electrophilicity of amide carbonyls, potential hydrolysis of the reaction intermediate and excess Addition of an organometallic reagent. This mini review focuses on the recent progress of total synthesis of complex alkaloids based on the Nucleophilic Additions to N-alkoxyamides, tertiary amides and secondary amides.
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Iridium-catalyzed chemoselective reductive Nucleophilic Addition to n -methoxyamides
Organic letters, 2015Co-Authors: Minami Nakajima, Takaaki Sato, Noritaka ChidaAbstract:Iridium-catalyzed reductive Nucleophilic Addition to N-methoxyamides is reported. The reaction took place in high yields in the presence of a variety of sensitive functional groups such as esters and nitro groups. Mechanistic studies revealed that the reaction of N-methoxyamides proceeded without equilibrium to an enamine intermediate in contrast to that with tert-amides.
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Chemoselective reductive Nucleophilic Addition to tertiary amides, secondary amides, and N-methoxyamides.
Chemistry (Weinheim an der Bergstrasse Germany), 2014Co-Authors: Minami Nakajima, Kenji Shirokane, Takaaki Sato, Yukiko Oda, Takamasa Wada, Ryo Minamikawa, Noritaka ChidaAbstract:As the complexity of targeted molecules increases in modern organic synthesis, chemoselectivity is recognized as an important factor in the development of new methodologies. Chemoselective Nucleophilic Addition to amide carbonyl centers is a challenge because classical methods require harsh reaction conditions to overcome the poor electrophilicity of the amide carbonyl group. We have successfully developed a reductive Nucleophilic Addition of mild nucleophiles to tertiary amides, secondary amides, and N-methoxyamides that uses the Schwartz reagent [Cp2 ZrHCl]. The reaction took place in a highly chemoselective fashion in the presence of a variety of sensitive functional groups, such as methyl esters, which conventionally require protection prior to Nucleophilic Addition. The reaction will be applicable to the concise synthesis of complex natural alkaloids from readily available amide groups.
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Nucleophilic Addition to N-alkoxyamides.
Organic & biomolecular chemistry, 2014Co-Authors: Takaaki Sato, Noritaka ChidaAbstract:An amide group is one of the most abundant functional groups in organic synthesis. However, Nucleophilic Addition to amide carbonyls has received less attention than their construction due to their high stability. In this Perspective, we describe our recent progress with N-alkoxyamides. Incorporation of an N-alkoxy group as a reactivity control element into the nitrogen atom of an amide successfully overcomes issues inherent to the Nucleophilic Addition. The reaction can introduce two different nucleophiles in a one-pot process, giving a variety of substituted amines. When the Schwartz reagent was used in the first reduction step, high chemoselectivity was observed in the presence of sensitive functional groups such as esters, which resulted in the concise total synthesis of (±)-gephyrotoxin.
Guangbin Jiang - One of the best experts on this subject based on the ideXlab platform.
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Palladium-Catalyzed Sequential Nucleophilic Addition/Oxidative Annulation of Bromoalkynes with Benzoic Acids To Construct Functionalized Isocoumarins
Organic letters, 2017Co-Authors: Guangbin Jiang, Chuanle Zhu, Huanfeng JiangAbstract:An efficient and robust protocol for the preparation of 3-substituted isocoumarins via palladium-catalyzed Nucleophilic Addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective Nucleophilic Addition and C–H functionalization procedure.
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Palladium-Catalyzed Sequential Nucleophilic Addition/Oxidative Annulation of Bromoalkynes with Benzoic Acids To Construct Functionalized Isocoumarins
2017Co-Authors: Guangbin Jiang, Chuanle Zhu, Huanfeng JiangAbstract:An efficient and robust protocol for the preparation of 3-substituted isocoumarins via palladium-catalyzed Nucleophilic Addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective Nucleophilic Addition and C–H functionalization procedure
Chuanle Zhu - One of the best experts on this subject based on the ideXlab platform.
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Palladium-Catalyzed Sequential Nucleophilic Addition/Oxidative Annulation of Bromoalkynes with Benzoic Acids To Construct Functionalized Isocoumarins
Organic letters, 2017Co-Authors: Guangbin Jiang, Chuanle Zhu, Huanfeng JiangAbstract:An efficient and robust protocol for the preparation of 3-substituted isocoumarins via palladium-catalyzed Nucleophilic Addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective Nucleophilic Addition and C–H functionalization procedure.
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Palladium-Catalyzed Sequential Nucleophilic Addition/Oxidative Annulation of Bromoalkynes with Benzoic Acids To Construct Functionalized Isocoumarins
2017Co-Authors: Guangbin Jiang, Chuanle Zhu, Huanfeng JiangAbstract:An efficient and robust protocol for the preparation of 3-substituted isocoumarins via palladium-catalyzed Nucleophilic Addition/oxidative annulation of bromoalkynes with benzoic acids has been developed. Remarkably, preliminary mechanistic studies indicated that the transformation might proceed via a stereo- and regioselective Nucleophilic Addition and C–H functionalization procedure
