87813-07-8Relevant articles and documents
Photoaddition reactions of azomethine ylides generated from α-aminonitriles to fullerene C60: Formation of fulleropyrrolidines and reaction efficiencies changes depending on reaction conditions
Lim, Suk Hyun,Cho, Dae Won
, (2019/10/03)
Photoaddition reactions of C60 with both (trimethylsilyl)methyl and either benzyl or phenethyl group containing α-aminonitriles were carried out to explore how product distributions and reaction efficiencies can be influenced by reaction solvent systems. The results show that photoreactions produce both trimethylsilyl- and cyano group containing fulleropyrrolidines as a major (or exclusive) product. Especially, photoreactions performed in either EtOH containing solution or oxygenated environment take place with a much more efficient manner.
Photochemical Approach for the Preparation of N-Alkyl/Aryl Substituted Fulleropyrrolidines: Photoaddition Reactions of Silyl Group Containing α-Aminonitriles with Fullerene C60
Lim, Suk Hyun,Oh, Jiin,Nahm, Keepyung,Noh, Sunguk,Shim, Jun Ho,Kim, Cheolhee,Kim, Eunae,Cho, Dae Won
, p. 1407 - 1420 (2019/01/30)
The photochemical reactions of C60 with N-(trimethylsilyl)methyl substituted and N-alkyl/aryl substituted α-aminonitriles were explored to evaluate the scope and reaction efficiency depending on the structural nature of amine substrates. The re
SET-promoted photoaddition reactions of fullerene C60 with tertiary N-trimethylsilylmethyl substituted α-aminonitriles. Approach to the synthesis of fulleropyrrolidine nitriles
Lim, Suk Hyun,Cho, Dae Won,Choi, Jungkweon,An, Hyunjun,Shim, Jun Ho,Mariano, Patrick S.
, p. 6249 - 6261 (2017/09/28)
Photoaddition reactions of C60 with tertiary N-arylmethyl-N-trimethylsilylmethyl substituted α-aminonitriles were explored. The results show that these photoreactions produce both trimethylsilyl- and cyano group containing fulleropyrrolidines as major products through pathways involving 1,3-dipolar cycloaddition of azomethine ylide intermediates. The ylides are formed either by SET from α-aminonitriles to the triplet excited state of C60 (in N2-purged solutions) followed by desilylation or deprotonation, or by hydrogen atom abstraction by singlet oxygen (in O2-purged solutions). In contrast, photoreactions of C60 with analogous amines that do not contain trimethylsilyl group form fulleropyrrolidines that contain aryl- and cyano substitutents on the pyrrolidine ring. The efficiencies of these photoaddition reactions are influenced by several factors including reaction condition (N2 or O2-purged), solvent polarity, the electronic and structural nature of α-aminonitriles and additive. The presence of trimethylsilyl group in the α-aminonitrile substrates plays a crucial role in enhancing the efficiencies of the fulleropyrrolidine forming reactions.
On the Use of N-amino Ethers as Capped Azomethine Ylide Equivalents
Padwa, Albert,Dent, William
, p. 235 - 244 (2007/10/02)
N-amino ethers have been found to act as azomethine ylide equivalents.Treatment of these compounds with lithium fluoride in the presence of a reactive dipolarophile afforded dipolar cycloadducts in high yield.The cycloaddition proceeded with complete stereospecificity with dimethyl fumarate and maleate.This result is consistent with the intermediacy of an azomethine ylide.The reaction of N-benzyl-N-(methoxymethyl)-N-amine afforded several silylated diamines when treated with zinc chloride or cesium fluoride in the absence of trapping agent.This can be attributed to an initial loss of the methoxy group to give a transient iminium ion.This species reacts further with the azomethine ylide or undergoes hydrolysis to give a silylated amine.The cycloaddition behavior of several unsymmetrically substituted azomethine ylide precursors was also examined.Competitive rate studies showed that the cycloaddition is compatible with a HOMO-controlled process.The regiochemistry of the cycloaddition, however, is not easily rationalized by simple FMO considerations and may instead be related to the charge transfer interaction energy of the reaction.
Diastereofacial selectivity in azomethine ylide cycloaddition reactions derived from chiral α-cyanoaminosilanes
Padwa, Albert,Chen, Yon-Yih,Chiacchio, Ugo,Dent, William
, p. 3529 - 3535 (2007/10/02)
A series of α-cyanoaminosilanes has been found to act as azomethine ylide equivalents. Treatment of these compounds with silver fluoride in the presence of electron deficient olefins gives substituted pyrrolidines in high yield. The extent ofdiastereoselectivity associated with the 1,3-dipolar cycloaddition of chiral azomethine ylides with several dipolarophiles has been studied. Reasonable levels of such diastereoselectivity have been found when optically active α-cyanoaminosilanes are employed as azomethine ylide equivalents. These compounds can be prepared in multigram quantities by treating the appropriate chiral amine with chlorotrimethylsilane followed by reaction of the resulting secondary amine with formaldehyde in the presence of potassium cyanide. It was found that N-benzyl-N-cyanomethyl-N-trimethylsilylmethylamine undergoes stereospecific cycloaddition with dimethyl fumarate and maleate. The stereospecificity of the reaction is consistent with a concerted cycloaddition reaction.
Synthetic Application of Cyanoaminosilanes as Azomethine Ylide Equivalents
Padwa, Albert,Chen, Yon-Yih,Dent, William,Nimmesgern, Hildegard
, p. 4006 - 4014 (2007/10/02)
A series of α-cyanoaminosilanes have been found to act as azomethine ylide equivalents.Treatment of these compounds with silver fluoride in the presence of electron-dificient alkynes and olefins gives substituted pyrroles and pyrrolidines in high yield.It was found that N-benzyl-N-(cyanomethyl)-N-amine undergoes stereospecific cycloaddition with dimethyl fumarate and maleate.The stereospecificity of the reaction is consistent with a concerted cycloaddition reaction.The cycloaddition behavior of an unsymmetrically substituted α-cyanosilylamine with methyl propiolate was also examined and found to react with high overall regioselectivity.The synthetic utility of cyanoaminosilanes as azomethine ylide equivalents was demonstrated by the preparation of a Reniera isoindole alkaloid.The key step in the synthesis involved the reaction of 2-methyl-3-methoxyquinone with N-methyl-N-(cyanomethyl)-N-amine in the presence of silver fluoride to give 2,5-dimethyl-6-methoxy-2H-isoindole-4,7-dione in good yield.
SYNTHESIS OF PYRROLIDINES USING AN α-CYANOAMINOSILANE AS AN AZOMETHINE YLIDE EQUIVALENT
Padwa, Albert,Chen, Yon-Yih
, p. 3447 - 3450 (2007/10/02)
The potential of α-cyanoaminosilane (3) to act as an azomethine ylide equivalent is illustrated by its treatment with silver fluoride in the presence of electron deficient olefins to give substituted pyrrolidines in high yield.
