Brønsted Acid Catalyzed Formal Insertion of Isocyanides into a C−O Bond of Acetals

Tobisu, Mamoru; Kitajima, Aki; Yoshioka, Setsuko; Hyodo, Isao; Oshita, Masayuki; Chatani, Naoto

doi:10.1021/ja073286h

Cited by 82 publications

(24 citation statements)

References 44 publications

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“…[59][60][61] Notably, these compounds are valuable intermediates in the synthesis of various pyrrolidine derivatives. [62][63][64][65][66][67][68] The reaction of sulfonylamides 13 with electron-rich aromatics actually led to the 1-sulfonyl-2-arylpyrrolidines 15 (Scheme 8). [59,[69][70][71] Alkyl, alkenyl, aryl, hetero-and polyaromatic substituents in sulfonylamides 13 are well tolerated, and yields of target compounds are generally good.…”

Section: Synthesis Of 2-arylpyrrolidines Via Intramolecular Cyclizatimentioning

confidence: 99%

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Acid‐Catalyzed Cascade Reaction of 4‐Aminobutanal Derivatives with (Hetero)aromatic Nucleophiles: A Versatile One‐Pot Access to 2‐(Hetero)arylpyrrolidines.

et al. 2019

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2‐(Hetero)arylpyrrolidine fragment is found in a diverse array of biologically active molecules, both natural and unnatural. In recent years, a substantial increase in number of approved drugs featuring this scaffold is observed. Developing methods for the synthesis of such compounds has been essential for making progress in this field. Most of these methods require usage of metal catalysts and introduce additional chemical steps to obtain appropriately substituted starting compounds. This microreview details the one‐pot approach for the synthesis of pyrrolidine derivatives possessing (hetero)aromatic substituent at the second position of pyrrolidine ring based on usage of readily available N‐substituted 4,4‐diethoxybutan‐1‐amines and (hetero)aromatics as starting compounds and Bronsted acids as catalysts.

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Section: Synthesis Of 2-arylpyrrolidines Via Intramolecular Cyclizatimentioning

confidence: 99%

“…Based on these data, we have developed a one‐pot approach to 1‐sulfonyl‐2‐ethoxypyrrolidines 14 via a reaction of 4,4‐diethoxybutan‐1‐amine with various sulfonyl chlorides (Scheme ) . Notably, these compounds are valuable intermediates in the synthesis of various pyrrolidine derivatives …”

Section: Introductionmentioning

confidence: 99%

Acid‐Catalyzed Cascade Reaction of 4‐Aminobutanal Derivatives with (Hetero)aromatic Nucleophiles: A Versatile One‐Pot Access to 2‐(Hetero)arylpyrrolidines.

et al. 2019

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“…Insertion of arylisonitrile into the C-O linkage of 3a gave α-methoxyimidate 7a. 35) Analogously, Hosomi-Sakurai reaction of acetal 3a with allyltrimethylsilane afforded ether 8a. 36,37) Overall, the present method allowed direct conversion of alkyne to a variety of substituted Markovnikov-type products, using methanol and nucleophiles.…”

Section: )mentioning

confidence: 99%

A Fluorinated Cobalt(III) Porphyrin Complex for Hydroalkoxylation of Alkynes

Ushimaru

Nishimura

Iwatsuki

et al. 2017

CHEMICAL & PHARMACEUTICAL BULLETIN

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A fluorinated cobalt(III) porphyrin complex [Co(TPFPP)- (Fig. 1). This method compares well with the earlier procedures catalyzed by Hg, 6,7) Pd, [8][9][10] Pt, 9,11,12) Au, [13][14][15][16][17][18][19][20][21][22] Ir [23][24][25][26] and Zn. 27)The active pentafluorophenylated Co III catalyst 1a was developed by structural modification of 1b used previously for alkyne hydration 2) (Fig. 1). Reaction of tetrakis(pentafluorophenyl) porphyrin (H 2 TPFPP) and cobalt(II) acetate 28) followed by aerobic oxidation in the presence of HNTf 2 and recrystallization from a mixture of chloroform, ethanol, and hexane afforded 1a in 67% yield. X-Ray structural analysis of 1a indicated that (1) the cobalt center adopts octahedral geometry, with porphyrin ligand in the equatorial positions and ethanol in the apical positions (Fig. 2); (2) Figure S1(a)].The catalyst 1a was found to be more reactive than 1b in the hydroalkoxylation of phenylacetylene (2a) with methanol (Table 1, entries 1 vs. 7). When a mixture of 2a (2.0 mmol), 1a (0.05 mol%), and HNTf 2 (0.18 mol%) in methanol (0.9 mL, 11 equiv) was heated at 70°C for 4 h under aerobic conditions, acetal 3a was obtained in 97% yield (entry 1).29) The initial turnover frequency (TOF) was 4000 h −1 (t=12 min). This value is comparable to those of gold catalysts and higher than those of catalysts based on other metals (entry 2). 30) Hydroalkoxylation of 2a in the absence of HNTf 2 required higher catalyst loading (entries 3 and 4). The reaction proceeded under N 2 atmosphere, but yielded 3a in a lower yield than that under air (entry 5 vs. entry 1). Double hydroalkoxylation of 2a at 27°C (room temperature) afforded acetal 3a in 97% yield (entry 6). Co III TPPCl [TPP=5,10,15, porphyrin] was less reactive than 1a and 1b (entry 8 vs. entries 1 and 7). The reaction hardly proceeded with analogous metal complexes such as Fe III TPPCl or Mn III TPPCl under otherwise identical conditions (entries 9 and 10).* To whom correspondence should be addressed. e-mail: h_naka@nagoya-u.jp

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“…Taguchi reported the direct alkylative Passerini reaction of aldehydes, isocyanides and a free aliphatic alcohol catalyzed by In(III) . Acetals and ketals are also useful for the reaction of an isocyanide catalyzed by Lewis or Brønsted acids, affording α‐alkoxyimidates …”

Section: O‐silylative Passerini Reactionmentioning

confidence: 99%

Carboxylic Acid Free Novel Isocyanide‐Based Reactions

Soeta

Ukaji

2014

The Chemical Record

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In order to develop a practical method for the construction of drug-like and heterocyclic compounds, we have designed a novel Passerini- or Ugi-type reaction system where a compound (which we write in the general form as Z-X) composed of an electrophilic (Z) and a nucleophilic group (X) could essentially perform the same function as the carboxylic acid. Based on this concept, we have developed the O-silylative Passerini reaction and the borinic acid catalyzed α-addition of isocyanides to aldehydes and water. In addition, we have designed and demonstrated the addition reaction of isocyanides to nitrones in the presence of TMSCl to afford the corresponding 1,2,3,4-tetrahydroisoquinoline-1-carboxyamides. Furthermore, a novel [5 + 1] cycloaddition of isocyanide was explored with C,N-cyclic N'-acyl azomethine imines as a "1,5-dipole" via a strategy involving intramolecular trapping of the isocyanide.

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Brønsted Acid Catalyzed Formal Insertion of Isocyanides into a C−O Bond of Acetals

Cited by 82 publications

References 44 publications

Acid‐Catalyzed Cascade Reaction of 4‐Aminobutanal Derivatives with (Hetero)aromatic Nucleophiles: A Versatile One‐Pot Access to 2‐(Hetero)arylpyrrolidines.

Acid‐Catalyzed Cascade Reaction of 4‐Aminobutanal Derivatives with (Hetero)aromatic Nucleophiles: A Versatile One‐Pot Access to 2‐(Hetero)arylpyrrolidines.

A Fluorinated Cobalt(III) Porphyrin Complex for Hydroalkoxylation of Alkynes

Carboxylic Acid Free Novel Isocyanide‐Based Reactions

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