<i>meso</i>-Trifluoromethyl-substituted Subporphyrin from Ring-splitting Reaction of <i>meso</i>-Trifluoromethyl-substituted [32]Heptaphyrin(1.1.1.1.1.1.1)

Sakamoto, Ryu; Saito, Shohei; Shimizu, Soji; Inokuma, Yasuhide; Aratani, Naoki; Osuka, Atsuhiro

doi:10.1246/cl.2010.439

Cited by 35 publications

(29 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…90 It has been thought that the transannular electronic interaction is enhanced at the hinge position of a figure-eight conformation of the octaphyrin upon the metalation. We have also demonstrated that the similar metathesislike splitting reactions of B(III)Cu(II) hybrid complexes of [32]heptaphyrins to B(III) [14]subporphyrin and Cu(II) [18]porphyrin, 91,92 the B(III) metalation-induced skeletal rearrangement from [28]hexaphyrin(1.1.1.1.1.1) to B(III) coordinated [28]hexaphyrin(2.1.1.0.1.1) via a transposition of a pentafluorophenyl-substituted meso-methine carbon, 93 Pd(II) metalation-induced formation of an N-confused porphyrin segment from [32]heptaphyrin substrates, 94 and Ni(II) metalation induced formation of a directly meso¢-linked diporphyrin. 95 The chemistry of expanded porphyrins have been reviewed elsewhere, 5255,96 where the emphasis was placed on the chemical reactivity and aromaticity.…”

mentioning

confidence: 73%

Subporphyrins: A Legitimate Ring-Contracted Porphyrin with Versatile Electronic and Optical Properties

Osuka

Tsurumaki

Tanaka

2011

Bulletin of the Chemical Society of Japan

Self Cite

118

View full text Add to dashboard Cite

After a brief survey of our efforts in the development of novel porphyrinoids that include mesomeso-linked porphyrin arrays, meso-aryl expanded porphyrins, and transition-metal-catalyzed functionalizations of porphyrins, a particular focus in this account is placed on the chemistry of subporphyrins that has been explored in our group. Subporphyrin is a legitimate ring-contracted porphyrin consisting of three pyrrolic subunits domed in a C 3 symmetric bowl shape. While subporphyrins are simple and small macrocycles and possess a key position in porphyrin chemistry, they had been elusive until our first synthesis of tribenzosubporphines in 2006. Shortly after, synthetic protocols of mesoaryl-substituted subporphyrins were developed to produce various subporphyrins with versatile electronic properties that can be widely tuned by meso-aryl substituents. Raney nickel reduction was used to prepare meso-alkyl-substituted subporphyrins from meso-thienyl-substituted subporphyrins. Subchlorins and subbacteriochlorins were prepared respectively by the reduction of subporphyrins with p-tosylhydrazide and Raney nickel. While subporphyrins and subchlorins share conjugated 14³-electronic circuits, subbacteriochlorins have a rare [13]diazaannulene circuit maintained through the lone-pair electrons of the nitrogen atom. The aromaticity decreases in the order of subporphyrin > subchlorin > subbacteriochlorin, as indicated from 1 H-and 11 B NMR spectra and nuclear independent chemical shift (NICS) calculations. Despite these progresses, the chemistry of subporphyrins is still in the infant stage with many untouched aspects and further improvements in synthetic yields are highly desirable for the developments of the chemistry of subporphyrins as well as their applications in diverse fields. A Brief Survey of Our Efforts in the Exploration of Novel PorphyrinoidsIn the last three decades, we have been involved in the exploration of novel porphyrinoids with intriguing structures, electronic and optical properties, and functions. We entered porphyrin chemistry with the aim to synthesize covalently linked organic constructs that can mimic the whole excitation energy transfer and electron transfer events of the photosynthetic reaction centers within a single molecular entity. 13 In the course of these studies, we fortunately encountered new reactions and structures, which drove us to change our research style from a well-designed, goal-orientated path to a flexible discovery-searching strategy to explore novel porphyrinoids. By following the flexible research style, we have explored mesomeso-linked Zn(II) porphyrin arrays, meso-aryl expanded porphyrins, transition-metal-catalyzed porphyrin modifications, and subporphyrins. After a brief survey of the former three topics, a particular focus is placed on the chemistry of subporphyrins that are legitimate ring-contracted porphyrins. As described below, subporphyrins are a new class of functional molecules, particularly in view of their highly tunable electronic and optical properties.

show abstract

mentioning

confidence: 73%

Subporphyrins: A Legitimate Ring-Contracted Porphyrin with Versatile Electronic and Optical Properties

Osuka

Tsurumaki

Tanaka

2011

Bulletin of the Chemical Society of Japan

Self Cite

118

View full text Add to dashboard Cite

show abstract

“…The unique chemical reactivity of expanded porphyrins means that they often undergo metalation‐induced skeletal rearrangements, as metalation reactions require specific coordination structures and expanded porphyrins have flexible electronic systems that are reactive toward such structural distortions 2. 3 The first examples of expanded porphyrins were the octaphyrins(1.1.1.0.1.1.1.0) reported by Vogel et al.,2 which were followed by our reports on 1) the splitting reaction of a bis(Cu II octaphyrin) into two Cu II porphyrins,3a,b 2) the boron(III)‐triggered splitting reaction of Cu II heptaphyrins to Cu II porphyrins and B III subporphyrins,3c,d and 3) the boron(III)‐induced rearrangement of a hexaphyrin(1.1.1.1.1.1) to form a hexaphyrin(2.1.1.0.1.1) 3e. These skeletal rearrangements are intriguing in making “chemical connections” between important porphyrinoids such as octaphyrins, heptaphyrins, hexaphyrins, porphyrins, and subporphyrins.…”

Section: Methodsmentioning

confidence: 83%

Palladium(II)‐Triggered Rearrangement of Heptaphyrins to N‐Confused Porphyrins

et al. 2011

Self Cite

View full text Add to dashboard Cite

show abstract

“…Later, several interesting reactions have been witnessed on octaphyrin ligands, including a splitting reaction of bis‐Cu II octaphyrin(1.1.1.1.1.1.1.1) into two Cu II porphyrins [2b,c] and Ni II metalation‐triggered metamorphosis of [36]octaphyrin(1.1.1.1.1.1.1.1) into rearranged mono‐Ni II octaphyrin, dioxygenated bis‐Ni II octaphyrin, and meso ‐ β ‐linked porphyrin dimer [2h] . Metalation‐triggered transannular bond formation has been also exemplified for pentaphyrins, hexaphyrins, and heptaphyrins [2d–g,i] . Inspired by these precedents, here we prepared a novel doubly meso ‐free octaphyrin 2 , and examined its metalations with Zn II and Ni II ions, which triggered the formations of directly fused dimers of porphyrin(2.1.1.1) and N‐confused porphyrin, respectively, via intramolecular transannular C−C bond formation (Figure 1).…”

Section: Figurementioning

confidence: 99%

Tetrabromo[36]octaphyrin: A Promising Precursor of Directly Fused Porphyrin(2.1.1.1) Dimer and meso‐α Fused N‐Confused Porphyrin Dimer

et al. 2021

Self Cite

View full text Add to dashboard Cite

3,7,23,27‐Tetrabromo[36]octaphyrin 2 was synthesized as a novel octaphyrin bearing two meso‐free positions. Surprisingly, its ZnII and NiII complexation reactions produced a directly fused porphyrin(2.1.1.1) dimer 6, and a meso‐α fused N‐confused porphyrin (NCP) dimer 7, as the first example of NCP tape, respectively, via transannular C−C bond formation. While 6 exhibits a diatropic ring‐current effect owing to the global 36π Möbius aromaticity, 7 shows a paratropic ring‐current effect due to the global Hückel 36π antiaromaticity. In addition, the oxidation of 7 with PbO2 allowed for formation of its two‐electron oxidized species 9 that exhibited a diatropic ring‐current effect due to the global Hückel 34π aromaticity. This work has demonstrated that meso‐free large expanded porphyrins can be a promising platform to produce novel fused porphyrinoids.

show abstract

meso-Trifluoromethyl-substituted Subporphyrin from Ring-splitting Reaction of meso-Trifluoromethyl-substituted [32]Heptaphyrin(1.1.1.1.1.1.1)

Cited by 35 publications

References 22 publications

Subporphyrins: A Legitimate Ring-Contracted Porphyrin with Versatile Electronic and Optical Properties

Subporphyrins: A Legitimate Ring-Contracted Porphyrin with Versatile Electronic and Optical Properties

Palladium(II)‐Triggered Rearrangement of Heptaphyrins to N‐Confused Porphyrins

Tetrabromo[36]octaphyrin: A Promising Precursor of Directly Fused Porphyrin(2.1.1.1) Dimer and meso‐α Fused N‐Confused Porphyrin Dimer

Contact Info

Product

Resources

About