1,3-Dipolar Cycloaddition of 2,6-Dichlorobenzonitrile Oxide to 2-Methyl-N-confused Porphyrin. Regio- and Stereoselective Synthesis and Structural Characterization of 2-Aza-21-carbabacteriochlorin and Resolution of 2-Aza-21-carbachlorin Enantiomers

• Published in: Journal of organic chemistry Vol. 77; no. 5; pp. 2431 - 2440
• Main Authors: Li, Xiaofang, Liu, Bin, Yu, Xianyong, Yi, Pinggui, Yi, Rongqiong, Chmielewski, Piotr J
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 02.03.2012; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Chlorobenzenes - chemistry; crystal structure; Cyclization; cycloaddition reactions; enantiomers; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with n hetero atom and also o and/or s, se, te hetero atoms; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Molecular Structure; Nitriles - chemistry; Organic chemistry; Physical Sciences; porphyrins; Porphyrins - chemical synthesis; Porphyrins - chemistry; Preparations and properties; Science & Technology; Stereoisomerism; stereoselective synthesis; X-ray diffraction; BIS-CHLORIN; PI-SYSTEM; N-CONFUSED PORPHYRIN; DIELS-ALDER REACTIONS; BARRELENE-FUSED CHLORINS; INVERTED PORPHYRIN; COMPLEXES; SUBSTITUTED PORPHYRINS; ENDOCYCLIC EXTENSION; ISOMER; 1,3-Dipolar cycloaddition; Nitrile; Regioselectivity; Nitrogen heterocycle; X ray diffraction; Characterization; Stereoselectivity; Enantiomer; Benzonitrile derivatives; Chemical synthesis; Porphyrin derivatives; Structural analysis; Oxygen nitrogen heterocycle; Crystalline structure
• ISSN: 0022-3263; 1520-6904; 1520-6904
• DOI: 10.1021/jo3000817

The 1,3-dipolar cycloaddition reaction of 2-methyl-N-confused porphyrin with 2,6-dichlorobenzonitrile oxide yielded four isomeric monoadducts of carbachlorin type and one diadduct of carbabacteriochlorin type. Two major carbachlorin products, constituting 82% of the monoadducts, were shown to be structural precursors of the unique 2-aza-21-carbabacteriochlorin. Enantiomers of the most abundant isomer of 2-aza-21-carbachlorin (55% of all carbachlorin products) have been resolved. The crystal structures of 2-aza-21-carbabacteriochlorin and the most abundant isomer of 2-aza-21-carbachlorin were characterized by X-ray diffraction.