Nickel-catalyzed asymmetric synthesis of P-stereogenic vinyl phosphines

Synlett ◽

10.1055/a-1695-4979 ◽

2021 ◽

Author(s):

xuteng liu ◽

Yue Wu ◽

Qingwei Zhang

Keyword(s):

Asymmetric Synthesis ◽

Recent Work ◽

Addition Reaction ◽

Efficient Strategy ◽

Secondary Phosphines

Addition reaction to alkynes is an efficient strategy for constructing valuable alkenyl compounds. However, the elusive regioselectivity has been a persistent challenge. In the context of hydrophosphination reaction which could afford valuable P-stereogenic phosphines, the control of enantioselectivity as well as regioselectivity were especially tricky. Here, we highlighted our recent work on the nickel catalyzed regio- and enantioselective hydrophosphination of unactivated alkynes with in situ generated secondary phosphines.

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Indium Bromide-catalyzed Unprecedented Hydrogenolysis: A Novel One-Pot Synthesis of Per-O-Acetylated β-carboxymethyl O and S-glycosides

Current Organic Chemistry ◽

10.2174/1385272824999200407093625 ◽

2020 ◽

Vol 24 (8) ◽

pp. 900-908

Author(s):

Ram Naresh Yadav ◽

Amrendra K Singh ◽

Bimal Banik

Keyword(s):

Asymmetric Synthesis ◽

Chiral Auxiliary ◽

Bioactive Molecules ◽

One Pot ◽

Enantiomerically Pure ◽

Stereoselective Glycosylation ◽

One Pot Synthesis ◽

Wide Range

Numerous O (oxa)- and S (thia)-glycosyl esters and their analogous glycosyl acids have been accomplished through stereoselective glycosylation of various peracetylated bromo sugar with benzyl glycolate using InBr3 as a glycosyl promotor followed by in situ hydrogenolysis of resulting glycosyl ester. A tandem glycosylating and hydrogenolytic activity of InBr3 has been successfully investigated in a one-pot procedure. The resulting synthetically valuable and virtually unexplored class of β-CMGL (glycosyl acids) could serve as an excellent potential chiral auxiliary in the asymmetric synthesis of a wide range of enantiomerically pure medicinally prevalent β-lactams and other bioactive molecules of diverse medicinal interest.

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How Artefacts Do Leadership: A Ventriloquial Analysis

Management Communication Quarterly ◽

10.1177/0893318921998078 ◽

2021 ◽

pp. 089331892199807

Author(s):

Jonathan Clifton ◽

Fernando Fachin ◽

François Cooren

Keyword(s):

Organizational Communication ◽

Recent Work ◽

Distributed Leadership ◽

Network Theory ◽

Actor Network Theory ◽

Fine Grained ◽

Naturally Occurring ◽

Human Actors

To date there has been little work that uses fine-grained interactional analyses of the in situ doing of leadership to make visible the role of non-human as well as human actants in this process. Using transcripts of naturally-occurring interaction as data, this study seeks to show how leadership is co-achieved by artefacts as an in-situ accomplishment. To do this we situate this study within recent work on distributed leadership and argue that it is not only distributed across human actors, but also across networks that include both human and non-human actors. Taking a discursive approach to leadership, we draw on Actor Network Theory and adopt a ventriloquial approach to sociomateriality as inspired by the Montreal School of organizational communication. Findings indicate that artefacts “do” leadership when a hybrid presence is made relevant to the interaction and when this presence provides authoritative grounds for influencing others to achieve the group’s goals.

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Strategies of In Situ Generated Magnesium Catalysis in Asymmetric Reactions

Synlett ◽

10.1055/a-1409-2734 ◽

2021 ◽

Author(s):

Dongxu Yang ◽

Linqing Wang

Keyword(s):

Asymmetric Synthesis ◽

Alkaline Earth ◽

Earth Metal ◽

Asymmetric Reactions ◽

Chiral Ligands ◽

Alkaline Earth Metal ◽

Enantioselective Reactions ◽

Earth's Crust

AbstractMagnesium (Mg) is a cheap, non-toxic, and recyclable alkaline earth metal that constitutes about 2% weight in the Earth’s crust. The use of magnesium catalysts to forge chiral moieties in molecules is highly attractive. Based on our work in recent years, we describe the current progress in the development of in situ generated magnesium catalysts and their application in asymmetric synthesis. In this perspective, a critically concise classification of in situ generated magnesium catalytic modes, with relevant examples, is presented, and representative mechanisms of each category are discussed. Building on the established diverse strategies, one can foresee that more innovative and structurally creative magnesium catalysts that are generated in situ will be developed to overcome more formidable challenges of catalytic enantioselective reactions.1 Introduction2 Magnesium Catalysts Generated in Situ from Chiral Ligands Containing Dual Reactive Hydrogens3 Magnesium Catalysts Generated in Situ from Monoanionic Chiral Ligands4 Bimetallic and Polymetallic Magnesium Catalysts Assembled in Situ5 Summary and Outlook

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II.—The Petrology of the Suffolx Box-stones (Crag)

Geological Magazine ◽

10.1017/s0016756800177830 ◽

1915 ◽

Vol 2 (6) ◽

pp. 250-259 ◽

Cited By ~ 5

Author(s):

P. G. H. Boswell

Keyword(s):

New Species ◽

Recent Work ◽

Early Pliocene ◽

Stone Material ◽

Molluscan Fauna ◽

Recent Account

Although much has been written upon the palæontology of the Suffolk box-stones, no description appears hitherto to have been published of the petrology of these boulders. This is the more curious on account of the light it might throw upon the disputed question of their source, no similar sandstone having yet been recognized with certainty in situ. The most recent account of the molluscan fauna is by my friend Mr. Alfred Bell. In a preliminary paper he has given a list of sixty-three species (excluding cetacean bones, teeth, crustaceans, etc.), about twelve new species and varieties being described. Mr. Bell has now kindly let me see in advance the MS. of a revised list of Mollusca (seventy-six species), much new box-stone material having been obtained in the last few years. As a result of recent work, he considers the affinities of the fauna to be rather with the Rupelian (Continental Oligocene) than with the Bolderian or Diestian, as he formerly thought. Mr. Clement Reid, in The Pliocene Deposits of Britain (Mem. Geol. Survey, 1890), considered the box-stones to be of about the same age as the Diestian Beds, but Mr. F. W. Harmer has, in later publications, been inclined to consider them to be rather older and of very early Pliocene age.

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