title: N- vs O-Coordination in cyclomanganation of 1,5-diaryl-3-(2-pyridyl)pentane-1,5-diones and 3-(2-pyridyl)chalcones; cyclomanganation at saturated carbon and the crystal structure of [1,5-diphenyl-κC2-3-(2-pyridyl- κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese

authors: Tully, Warren

subjects: Manganese

abstract: Reaction of 1,5-diphenyl-3-(2-pyridyl)pentane-1,5-dione (5a) with 2.5 moles of benzylpentacarbonylmanganese in petroleum spirit under reflux gives a small amount of the symmetric di-aryl-manganated product [1,5-diphenyl-κC2-3-(2-pyridyl)pentane-1,5-dione-κO1κO5]bis-(tetracarbonylmanganese) (7a), but mostly [1,5-diphenyl-κC2-3-(2-pyridyl-κN)pentan-2-yl- κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6a) which is manganated at only one aryl carbon [by Mn(CO)4] but also [by Mn(CO)3 with N and O coordination] at the methylene carbon adjacent to the Mn(CO)4-coordinated ketone carbonyl. The latter is a rare example of direct cyclomanganation at a saturated carbon and the only known case adjacent to a carbonyl group; the X-ray crystal structure of 6a is reported. With 3 moles of benzylpentacarbonylmanganese the yield of 6a remains unchanged but some trimanganation product [1,5-diphenyl-κC2′κC2 -3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tris-(tetracarbonylmanganese) (8a) is formed, presumably from 7a. Routes to products are proposed and activating factors considered. 1,5-Di-(2-thienyl)-3-(2-pyridyl)pentane-1,5-dione (5b) and its 3-thienyl isomer (5c) similarly give 6a analogues [1,5-di-(2-thienyl-κC3)-3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6b) and [1,5-di-(3-thienyl-κC2)-3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6c).
Also reported are the mono-cyclomanganation product [1-(2,6-dimethoxyphenyl)-3-(2-pyridyl-κN)prop-2-en-2-yl-κC2-1-one]tetracarbonylmanganese (16) and dicyclomanganation product [1-(2,5-dimethyl-3-thienyl-κC4)-3-(2-pyridyl-κN)prop-2-en-2-yl- κC2-1-one-κO ]bis-(tetracarbonylmanganese) (17) from reaction of the respective (E)-1-aryl-3-(2-pyridyl)prop-2-en-1-ones (3-(2-pyridyl)chalcones), the first reported examples of enone metallation at the α-carbon via N-coordination by a β-2-pyridyl group.

text: N- vs O-Coordination in cyclomanganation of 1,5-diaryl-3-(2-pyridyl)pentane-1,5-diones and 3-(2-pyridyl)chalcones; cyclomanganation at saturated carbon and the crystal structure of [1,5-diphenyl-κC2-3-(2-pyridyl- κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese Reaction of 1,5-diphenyl-3-(2-pyridyl)pentane-1,5-dione (5a) with 2.5 moles of benzylpentacarbonylmanganese in petroleum spirit under reflux gives a small amount of the symmetric di-aryl-manganated product [1,5-diphenyl-κC2-3-(2-pyridyl)pentane-1,5-dione-κO1κO5]bis-(tetracarbonylmanganese) (7a), but mostly [1,5-diphenyl-κC2-3-(2-pyridyl-κN)pentan-2-yl- κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6a) which is manganated at only one aryl carbon [by Mn(CO)4] but also [by Mn(CO)3 with N and O coordination] at the methylene carbon adjacent to the Mn(CO)4-coordinated ketone carbonyl. The latter is a rare example of direct cyclomanganation at a saturated carbon and the only known case adjacent to a carbonyl group; the X-ray crystal structure of 6a is reported. With 3 moles of benzylpentacarbonylmanganese the yield of 6a remains unchanged but some trimanganation product [1,5-diphenyl-κC2′κC2 -3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tris-(tetracarbonylmanganese) (8a) is formed, presumably from 7a. Routes to products are proposed and activating factors considered. 1,5-Di-(2-thienyl)-3-(2-pyridyl)pentane-1,5-dione (5b) and its 3-thienyl isomer (5c) similarly give 6a analogues [1,5-di-(2-thienyl-κC3)-3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6b) and [1,5-di-(3-thienyl-κC2)-3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6c).
Also reported are the mono-cyclomanganation product [1-(2,6-dimethoxyphenyl)-3-(2-pyridyl-κN)prop-2-en-2-yl-κC2-1-one]tetracarbonylmanganese (16) and dicyclomanganation product [1-(2,5-dimethyl-3-thienyl-κC4)-3-(2-pyridyl-κN)prop-2-en-2-yl- κC2-1-one-κO ]bis-(tetracarbonylmanganese) (17) from reaction of the respective (E)-1-aryl-3-(2-pyridyl)prop-2-en-1-ones (3-(2-pyridyl)chalcones), the first reported examples of enone metallation at the α-carbon via N-coordination by a β-2-pyridyl group.

year: 2005-07-01

title: Learning structure from sequences, with applications in a digital library

authors: Witten, Ian H.

subjects: computer science

abstract: The services that digital libraries provide to users can be greatly enhanced by automatically gleaning certain kinds of information from the full text of the documents they contain. This paper reviews some recent work that applies novel techniques of machine learning (broadly interpreted) to extract information from plain text, and puts it in the context of digital library applications. We describe three areas: hierarchical phrase browsing, including efficient methods for inferring a phrase hierarchy from a large corpus of text; text mining using adaptive compression techniques, giving a new approach to generic entity extraction, word segmentation, and acronym extraction; and keyphrase extraction.

text: Learning structure from sequences, with applications in a digital library The services that digital libraries provide to users can be greatly enhanced by automatically gleaning certain kinds of information from the full text of the documents they contain. This paper reviews some recent work that applies novel techniques of machine learning (broadly interpreted) to extract information from plain text, and puts it in the context of digital library applications. We describe three areas: hierarchical phrase browsing, including efficient methods for inferring a phrase hierarchy from a large corpus of text; text mining using adaptive compression techniques, giving a new approach to generic entity extraction, word segmentation, and acronym extraction; and keyphrase extraction.

year: 2002

title: Art, the aesthetics, and ethics of tattooing at Flax Roots Tattoo Studio

authors: Shaver, Mandy (Amanda)

subjects: aesthetic

abstract: Flax Roots Tattoo Studio, a tattoo business in Hamilton, Waikato, New Zealand, offers clients different styles of tattooing to choose from, i.e. Moko, Traditional European, Portrait, and Traditional American. Tattoo artists and their clients differ in ethnicity, nationality, religion, sex, occupation, age, hobbies, and so on.  Anthropological research and philosophical insight provided the framework texts for my case study.  My fieldwork consisted of semi-structured interviews and photographs of artists and clients.  By participating in tattooing, these individuals influence the art and the aesthetic tastes of their local culture.  Additionally, tattoo artists follow an ethical code that dictates how to run their business, preserve their art, and protect their clients.  By choosing Flax Roots Tattoo Studio as my fieldwork site, I was able to answer the questions: 1. How do tattoo artists and their clients engage with and shape tattoo art and its aesthetic at Flax Roots Tattoo Studio? ; and 2. How do these tattoo artists’ ethics influence their relationships with their clients and art?

text: Art, the aesthetics, and ethics of tattooing at Flax Roots Tattoo Studio Flax Roots Tattoo Studio, a tattoo business in Hamilton, Waikato, New Zealand, offers clients different styles of tattooing to choose from, i.e. Moko, Traditional European, Portrait, and Traditional American. Tattoo artists and their clients differ in ethnicity, nationality, religion, sex, occupation, age, hobbies, and so on.  Anthropological research and philosophical insight provided the framework texts for my case study.  My fieldwork consisted of semi-structured interviews and photographs of artists and clients.  By participating in tattooing, these individuals influence the art and the aesthetic tastes of their local culture.  Additionally, tattoo artists follow an ethical code that dictates how to run their business, preserve their art, and protect their clients.  By choosing Flax Roots Tattoo Studio as my fieldwork site, I was able to answer the questions: 1. How do tattoo artists and their clients engage with and shape tattoo art and its aesthetic at Flax Roots Tattoo Studio? ; and 2. How do these tattoo artists’ ethics influence their relationships with their clients and art?

year: 2018