Reactions of Antiaromatic Norcorrole Ni(II) Complex with Carbenes

Abstract

Norcorrole is a ring-contracted porphyrinoid, exhibiting distinct antiaromaticity. Herein, we report the reactions of meso-dimesitylnorcorrole Ni­(II) complex with two types of carbenes: dichlorocarbene and an N-heterocyclic carbene (NHC). The reaction with in-situ-generated dichlorocarbene resulted in the double insertion of two chloromethine units to provide a mixture of 5,15-dichloroporphyrin and chlorinated isopyricorroles. The nucleophilic NHC attacked the 3-position of the norcorrole core and the subsequent proton transfer furnished a nonconjugated macrocycle incorporating a diazafulvene segment.

Molecular Systems Combining Porphyrinoids and N‐Heterocyclic Carbenes

“…Moreover, the dispersity (Ð M ) values determined by Size Exclusion Chromatography (SEC) are within the range of 1.03-1. 60. The obtained data demonstrate that the studied polymerization reactions are wellcontrolled.…”

“…The reaction with in situ generated dichlorocarbene resulted in the double insertion of two chloromethine units to provide a mixture of 5,15‐dichloroporphyrin 56 and chlorinated isopyricorroles 57 (Scheme 22). [60] The ring expansion reaction to obtain the pyridine ring involves the preliminary formation of a cyclopropane ring through the addition of dichlorocarbene to a β , β ′‐pyrrolic bond. NHCs exhibited a different reactivity towards norcorroles.…”

Nucleophilic Aromatic Substitution (SNAr) and Related Reactions of Porphyrinoids: Mechanistic and Regiochemical Aspects

“…Similarly, ring expansions were observed in reactions of norcorroles with carbenes by Liu et al [ 255 ] Exposing 190 to dichlorocarbene 209 or N ‐heterocyclic carbene (NHC) 208 yielded multiple products. First, treatment of 190 with 208 gave the diazafulvene‐substituted macrocycle 204 in 46 %, with the nucleophile attacking in the expected place for this macrocyclic skeleton (vide infra).…”

“…Reactions of norcorroles with carbenes and silylenes to yield expanded norcorroles, and other macrocycles. [ 254,255 ] …”

Progress in the Synthesis and Derivatization of Norcorrole

“…Shinokubo 为了试验硅插入的可能性, 将芳香性卟啉 13 与 硅烯 14 反应, 结果未观察到任何反应, 镍(II)去甲咔咯 却在室温下能迅速与硅烯生成插入产物 15 [31] . 值得一 提的是, 不同浓度下的反应有所不同: 与适量的环扩张 试剂硅烯反应, 基于硅烯插入到镍(II)去甲咔咯的反应, Shinokubo 课题组 [32] 又研究发现了镍(II)去甲咔咯可以与原位生成 的二氯卡宾反应. 镍(II)去甲咔咯与原位生成的二氯卡 除了与卡宾反应外, 我们课题组发现了 3-硝基镍 (II)去甲咔咯还能与炔反应插入碳原子.…”