A silyl-mediated [3+2] photochemical cycloaddition

Michael G Organ; Debasis Mallik

doi:10.1139/v06-077

A silyl-mediated [3+2] photochemical cycloaddition

Canadian Journal of Chemistry ◽

10.1139/v06-077 ◽

2006 ◽

Vol 84 (10) ◽

pp. 1259-1262 ◽

Cited By ~ 4

Author(s):

Michael G Organ ◽

Debasis Mallik

Keyword(s):

Ring Expansion ◽

One Step

The generation of larger rings from intermediate cyclobutanes via a two-step [2+2] photocycloaddition – ring expansion, known as the de Mayo reaction, has been widely applied in synthesis. Herein a one-step synthesis of cyclopentanoids has been developed based on the photochemical irradiation of an enone in the presence of an allylsilane. The ability of the silyl moiety to stabilize the intermediate biradical is believed to be responsible for this unique transformation where one normally expects to see the [2+2] cyclobutane adduct.Key words: [2+2] photocycloaddition - ring expansion, allylsilanes, cyclopentanoids, photochemical.

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Carbodiimide insertion into sulfonimides: one-step route to azepine derivatives via a two-atom saccharin ring expansion

Chemical Communications ◽

10.1039/c6cc07331j ◽

2017 ◽

Vol 53 (5) ◽

pp. 901-904 ◽

Cited By ~ 13

Author(s):

Davin Tan ◽

Tomislav Friščić

Keyword(s):

Ring Expansion ◽

Insertion Reaction ◽

Direct Expansion ◽

One Step

A novel carbodiimide insertion reaction enables a one-step, two-atom expansion of cyclic and linear sulfonimides, including the first direct expansion of saccharin into thiadiazepines.

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One-step construction of complex polyheterocycles via a sequential post-GBB cyclization/spiro ring expansion triggered by a [1,5]-hydride shift

Organic Chemistry Frontiers ◽

10.1039/c8qo00071a ◽

2018 ◽

Vol 5 (10) ◽

pp. 1628-1632 ◽

Cited By ~ 12

Author(s):

Sandip Gangadhar Balwe ◽

Yeon Tae Jeong

Keyword(s):

Ring Expansion ◽

Hydride Shift ◽

One Step

An efficient tandem route to novel amino-indazolo[3′,2′:2,3]imidazo[1,5-c]quinazolin-6(5H)-ones has been explored.

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One-Step Conversion of Oxetane-Fused to 1,3-Oxazine-Fused Steroids

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19981613 ◽

1998 ◽

Vol 63 (10) ◽

pp. 1613-1622 ◽

Cited By ~ 8

Author(s):

Andrea Hajnal ◽

János Wölfling ◽

Gyula Schneider

Keyword(s):

Diethyl Ether ◽

Ring Expansion ◽

Aryl Nitriles ◽

One Step ◽

Ring Expansion Reaction ◽

Ether Complex

In a ring-expansion reaction, alkyl and aryl nitriles, in the presence of tetrafluoroboric acid-diethyl ether complex, react with 3-methoxy-16β,17β-dihydro-4'H-oxeto[3',2':16,17]estra-1,3,5(10)-triene to give 3-methoxy-16β,17β-dihydro-4'H-[1,3]-oxazino[5',6':16,17]estra-1,3,5(10)-triene derivatives. Under similar conditions 3-methoxy-16α,17α-dihydro-4'H-oxeto[3',2':16,17]estra-1,3,5(10)-triene undergoes a Wagner-Meerwein rearrangement.

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Visible-light mediated oxidative ring expansion of anellated cyclopropanes to fused endoperoxides with antimalarial activity

Organic Chemistry Frontiers ◽

10.1039/d0qo00168f ◽

2020 ◽

Vol 7 (14) ◽

pp. 1789-1795

Author(s):

Simon Budde ◽

Felix Goerdeler ◽

Johannes Floß ◽

Peter Kreitmeier ◽

Elliot F. Hicks ◽

...

Keyword(s):

Visible Light ◽

Antimalarial Activity ◽

Ring Expansion ◽

One Step ◽

Oxidative Ring Expansion

Hetero- and carbocyclic anellated cyclopropanes were converted in one step by a visible light induced photooxidation to their corresponding polycyclic endoperoxides, which show promising antimalarial activity.

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An Interactive Minicomputer Program for the Indexing and Simulation of Electron Diffraction Patterns

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100092670 ◽

1976 ◽

Vol 34 ◽

pp. 542-543

Author(s):

R.P. Goehner ◽

W.T. Hatfield ◽

Prakash Rao

Keyword(s):

Electron Diffraction ◽

Real Time ◽

Pattern Analysis ◽

Flow Diagram ◽

Hard Copy ◽

Time Analysis ◽

Real Time Analysis ◽

Transmission Electron ◽

One Step ◽

Diffraction Patterns

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.

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Nutrient-regulated gene expression in eukaryotes

Biochemical Society Symposium ◽

10.1042/bss0730085 ◽

2006 ◽

Vol 73 ◽

pp. 85-96 ◽

Cited By ~ 8

Author(s):

Richard J. Reece ◽

Laila Beynon ◽

Stacey Holden ◽

Amanda D. Hughes ◽

Karine Rébora ◽

...

Keyword(s):

Gene Expression ◽

Rna Polymerase ◽

Rna Polymerase Ii ◽

Transcriptional Control ◽

Direct Interaction ◽

Signalling Pathways ◽

A Cell ◽

One Step ◽

Higher Eukaryotes ◽

Regulated Gene Expression

The recognition of changes in environmental conditions, and the ability to adapt to these changes, is essential for the viability of cells. There are numerous well characterized systems by which the presence or absence of an individual metabolite may be recognized by a cell. However, the recognition of a metabolite is just one step in a process that often results in changes in the expression of whole sets of genes required to respond to that metabolite. In higher eukaryotes, the signalling pathway between metabolite recognition and transcriptional control can be complex. Recent evidence from the relatively simple eukaryote yeast suggests that complex signalling pathways may be circumvented through the direct interaction between individual metabolites and regulators of RNA polymerase II-mediated transcription. Biochemical and structural analyses are beginning to unravel these elegant genetic control elements.

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