Molecules

6 pages, 78 KiB

Open AccessArticle

Cohalogenation of Allyl and Vinylsilanes using Polymer-bound Haloate(I)-Reagents

by Silvie Domann, Georgia Sourkouni-Argirusi, Nuria Merayo, Andreas Schönberger and Andreas Kirschning

Molecules 2001, 6(1), 61-66; https://doi.org/10.3390/60100061 - 16 Jan 2001

Cited by 6 | Viewed by 7399

Abstract

Polymer-supported electrophilic halogenate(I) complexes 2 and 3 promote smooth addition to vinyl and allylsilanes without loss of the silyl group. In conjunction with Amberlyst A26 (OH⁻ -form) vinyl silanes are converted into epoxysilanes. Full article

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9 pages, 106 KiB

Open AccessArticle

Sensitized Photooxygenation of Cholesterol and Pseudocholesterol Derivatives via Singlet Oxygen

by Wu Shuping, Jiang Zhiqin, Li Heting, Yang Li and Zeng Daixun

Molecules 2001, 6(1), 52-60; https://doi.org/10.3390/60100052 - 16 Jan 2001

Cited by 11 | Viewed by 8041

Abstract

3-Substituted cholesterols and 7-substituted pseudocholesterols undergo a facile photooxygenation sensitized by 9, 10-dicyanoanthracene (DCA) and lumiflavin (LF) to give similar, oppositely-positioned enol derivatives. Both steroids showed the same reaction pattern associated with the endocyclic 5- and 4-olefin units, respectively. The reaction was proposed [...] Read more.

3-Substituted cholesterols and 7-substituted pseudocholesterols undergo a facile photooxygenation sensitized by 9, 10-dicyanoanthracene (DCA) and lumiflavin (LF) to give similar, oppositely-positioned enol derivatives. Both steroids showed the same reaction pattern associated with the endocyclic 5- and 4-olefin units, respectively. The reaction was proposed to proceed via the ene reaction of singlet oxygen and subsequent rearrangement of the initially formed 5a-hydroperoxides. Full article

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5 pages, 40 KiB

Open AccessArticle

A Simple Method for Synthesis of Active Esters of Isonicotinic and Picolinic Acids

by Jørn B. Christensen

Molecules 2001, 6(1), 47-51; https://doi.org/10.3390/60100047 - 16 Jan 2001

Cited by 27 | Viewed by 11743

Abstract

A method for preparation of the p-nitrophenyl-, N-hydroxysuccinimidyl- and pentafluorophenyl esters of isonicotinic and picolinic acids from the corresponding acids is reported. Full article

26 pages, 272 KiB

Open AccessReview

Bile Acids as Building Blocks of Supramolecular Hosts

by Jari Tamminen and Erkki Kolehmainen

Molecules 2001, 6(1), 21-46; https://doi.org/10.3390/60100021 - 16 Jan 2001

Cited by 186 | Viewed by 13411

Abstract

A review of the use of bile acid-based compounds as building blocks for designing novel supramolecular hosts for molecular recognition is presented. Pharmacological applications and the newest spectroscopic and computational studies of bile acid derivatives are also shortly considered. Full article

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8 pages, 82 KiB

Open AccessArticle

Tricarbonyl(h6-Arene)Chromium(0) Complexes as Chiral Auxiliaries: Asymmetric Synthesis of b-Lactones

by Paola Del Buttero and Deborah Montrasio

Molecules 2001, 6(1), 13-20; https://doi.org/10.3390/60100013 - 16 Jan 2001

Cited by 3 | Viewed by 7351

Abstract

The optically pure tricarbonyl(h⁶-2-substituted benzaldehydes)chromium are used as chiral auxiliaries in the condensation with a series of doubly lithiated carboxylic acids. The intramolecular ring closure of the obtained Cr(CO)₃ complexed b-hydroxyacids affords the optically pure b-lactones in satisfactory yield. Full article

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12 pages, 105 KiB

Open AccessReview

Synthesis of Polycyclic Ring Systems Using Transition Metal Catalyzed Cyclizations of Diazo Alkynyl Ketones

by Albert Padwa

Molecules 2001, 6(1), 1-12; https://doi.org/10.3390/60100001 - 22 Dec 2000

Cited by 26 | Viewed by 9764

Abstract

The rhodium(II)-catalyzed reaction of α-diazo ketones bearing tethered alkyne units represents a new and useful method for the construction of a variety of substituted cyclopentenones. The process proceeds by addition of the rhodium-stabilized carbenoid onto the acetylenic π-bond to give a vinyl carbenoid [...] Read more.

The rhodium(II)-catalyzed reaction of α-diazo ketones bearing tethered alkyne units represents a new and useful method for the construction of a variety of substituted cyclopentenones. The process proceeds by addition of the rhodium-stabilized carbenoid onto the acetylenic π-bond to give a vinyl carbenoid intermediate. The resulting rhodium complex undergoes a wide assortment of reactions including cyclopropanation, 1,2-hydrogen migration, CH-insertion, addition to tethered alkynes and ylide formation. When 2-alkynyl-2-diazo-3-oxobutanoates were treated with a Rh(II)-catalyst, furo[3,4-c]furans were formed in excellent yield. Full article

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1 pages, 13 KiB

Open AccessEditorial

Invitation: High Quality Papers with Extensive Literature Review and Full Experimental Details

by Derek J. McPhee and Shu-Kun Lin

Molecules 2001, 6(1), 601000; https://doi.org/10.3390/6010000i - 20 Jan 2000

Cited by 2 | Viewed by 2954

Abstract

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Molecules, Volume 6, Issue 1 (January 2001) – 7 articles , Pages 1-66, Article 601000

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