Publications by authors named "M SUMIMOTO"
In this study, we discovered a directed nucleophilic aromatic substitution reaction, "directed SNAr (dSNAr)," in the reaction of -iodobezamides and amine in the presence of pyridine. The reaction proceeded -specifically and did not require a strong electron-withdrawing group on the arene substrate. Most reactions proceeded at room temperature in the presence of Py, and a wide range of amine nucleophiles can be applied.
View Article and Find Full Text PDFColor change of materials by external stimulus has attracted much attention for various applications. We synthesized 1,3-bis(3,3-dimethyl-2-methylene indolenine)squaraine (ISQ), which was a yellow powder with golden luster (ISQ(gold)) and whose color changed to blue (ISQ(blue)) by being ground using mortar and pestle. Scanning electron microscopy indicated that ISQ(gold) consisted of laminated plate-like crystals with a large flat surface, which was attributable to (2 0-2) facets of monoclinic crystals.
View Article and Find Full Text PDFThe Prilezhaev reaction produces epoxides using alkenes and peroxy acids such as -chloroperoxybenzoic acid (CPBA). The reaction proceeds a concerted mechanism in one step. Although the CPBA used in organic syntheses contains water because of its explosive nature, the effects of water on the reaction have not been considered.
View Article and Find Full Text PDFThe mechanism of the phenol-epoxide ring-opening reaction using tetraphenylphosphonium-tetraphenylborate (TPP-K) was investigated using the density functional theory (DFT) method. The reaction was initiated by breaking the P-B bond of TPP-K. The generated tetraphenylborate (TetraPB) reacted with phenol to form a phenoxide ion, which combined with tetraphenylphosphonium (TPP) to produce the active species, i.
View Article and Find Full Text PDFChemistry of Tertiary Carbon Center in the Formation of Congested C-O Ether Bonds.
Angew Chem Int Ed Engl
February 2021
Article Synopsis
- Nucleophilic substitutions, particularly S1 and S2 reactions, are reliable for many processes but struggle with bulky nucleophiles and chiral tertiary alkyl electrophiles when creating chiral quaternary carbon centers.
- An S1 reaction using radical species can handle bulky nucleophiles and alkyl halides, but still lacks feasibility with chiral tertiary alkyl electrophiles.
- This paper explores a novel reaction using tertiary alkyl alcohols and non-chiral or chiral α-bromocarboxamides to synthesize congested ether compounds featuring two different tertiary alkyl groups, while maintaining stereoretention.