A novel case of atom-efficient C−C bond formation of small molecules catalyzed by the facile organoaluminum compound

2021 ◽  
pp. 121879
Author(s):  
Yunzhou Zhao ◽  
Xiaoli Ma ◽  
Ben Yan ◽  
Congjian Ni ◽  
Xing He ◽  
...  
Keyword(s):  
Small Molecules ◽  
Bond Formation ◽  
Organoaluminum Compound

scholarly journals Facile N-functionalization and strong magnetic communication in a diuranium(v) bis-nitride complex

2019 ◽  
Vol 10 (12) ◽  
pp. 3543-3555 ◽  
Author(s):  
Luciano Barluzzi ◽  
Lucile Chatelain ◽  
Farzaneh Fadaei-Tirani ◽  
Ivica Zivkovic ◽  
Marinella Mazzanti
Keyword(s):  
Small Molecules ◽  
Bond Formation ◽  
Antiferromagnetic Coupling ◽  
Ambient Conditions ◽  
C And N

A diuranium(v) bis-nitride complex supported by siloxide ligands displays remarkable reactivity in ambient conditions with small molecules such as CS2, CO2, CO and H2 resulting in N–C and N–H bond formation. The nitride linker also leads to an unusually strong antiferromagnetic coupling between uranium(v) ions.

scholarly journals Iterative Synthesis of Pluripotent Thioethers through Controlled Redox Fluctuation of Sulfur

Synlett ◽  
2018 ◽  
Vol 29 (10) ◽  
pp. 1329-1333 ◽  
Author(s):  
Abraham Mendoza ◽  
Kilian Colas
Keyword(s):  
Small Molecules ◽  
Redox State ◽  
Bond Formation ◽  
Building Blocks ◽  
Constructive Alignment ◽  
Boronic Esters ◽  
Type C ◽  
Iterative Synthesis

Target- and diversity-oriented syntheses are based on diverse building blocks, whose preparation requires discrete design and constructive alignment of different chemistries. To enable future automation of the synthesis of small molecules, we have devised a unified strategy that serves the divergent synthesis of unrelated scaffolds such as carbonyls, olefins, organometallics, halides, and boronic esters. It is based on iterations of a nonelectrophilic Pummerer-type C–C coupling enabled by turbo-organomagnesium amides that we have recently reported. The pluripotency of sulfur allows the central building blocks to be obtained by regulating C–C bond formation through control of its redox state.

Recent Advances for the C–C and C–N Bond Formation in the Synthesis­ of 1-Phenethyl-tetrahydroisoquinoline, Aporphine, Homoaporphine­, and β-Carboline Alkaloids

Synthesis ◽  
2017 ◽  
Vol 49 (20) ◽  
pp. 4535-4561 ◽  
Author(s):  
Carlos Puerto Galvis ◽  
Vladimir Kouznetsov
Keyword(s):  
Small Molecules ◽  
Control Strategies ◽  
Bond Formation ◽  
Biological Properties ◽  
Physical Activities ◽  
Organic Transformations ◽  
Reaction Step ◽  
Critical Step ◽  
Metal Catalyzed ◽  
Made In

Among the existing methods for the synthesis of bioactive and/or complex small molecules, organic transformations such as C–C and C–N bond formation have been significantly developed and exploited for the synthesis of diverse synthetic and natural fused aza-polycycles. The abundance and biological and physical activities of 1-phenethyl-tetrahydroisoquinolines, aporphines, homoaporphines, and β-carbolines have inspired many organic chemists to seek sustainable and efficient protocols for their preparation. However, these methodologies involve multiple steps and in most cases the key reaction step is based on the formation of new C–C and/or C–N bonds, and this is usually the critical step that lowers the yields and selectivity. This review is focused on the advances made in recent years regarding the synthesis of these selected natural fused aza-polycycles, overviewing the substrate scope, limitations, regioselectivity, and chemoselectivity, as well as related control strategies of these reactions, concentrating on developments from 2010 to 2016.1 Introduction2 1-Phenethyl-tetrahydroisoquinolines; Dysoxylum Alkaloids3 Aporphines, Homoaporphines, and Semisynthetic Derivatives4 Harmala and Eudistomin Alkaloids and Their Biological Properties5 Metal-Catalyzed C–C Bond Formation6 Pd-Catalyzed C–C and C–N Bond Formation7 Metal-Catalyzed C–N Bond Formation8 [4+2] Cycloaddition in the Synthesis Of Aporphines9 Tandem C–N/C–C Bond Formation: The Pictet–Spengler Reaction10 Miscellaneous Methods11 Conclusions

Gap junctions in the prothoracic glands of the tobacco hornworm, Manduca sexta

1992 ◽  
Vol 50 (1) ◽  
pp. 706-707
Author(s):  
Ji-da Dai ◽  
M. Joseph Costello ◽  
Lawrence I. Gilbert
Keyword(s):  
Gap Junctions ◽  
Small Molecules ◽  
Manduca Sexta ◽  
Freeze Fracture ◽  
Cell Communication ◽  
Cellular Level ◽  
Thin Sections ◽  
Prothoracic Glands ◽  
Polyhydroxylated Steroids ◽  
Stimulation Of

Insect molting and metamorphosis are elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands (PGs). Prothoracicotropic hormone stimulation of steroidogenesis by the PGs at the cellular level involves both calcium and cAMP. Cell-to-cell communication mediated by gap junctions may play a key role in regulating signal transduction by controlling the transmission of small molecules and ions between adjacent cells. This is the first report of gap junctions in the PGs, the evidence obtained by means of SEM, thin sections and freeze-fracture replicas.

Fusion and Fission Processes in Exocytosis: Possible Roles for Synexin and Osmotic Lysis in the Two Events

1980 ◽  
Vol 38 ◽  
pp. 594-597
Author(s):  
H.B. Pollard ◽  
C.E. Creutz ◽  
C.J. Pazoles ◽  
J.H. Scott
Keyword(s):  
Small Molecules ◽  
Chromaffin Cells ◽  
Adrenal Glands ◽  
General Concept ◽  
Extracellular Calcium ◽  
Large Protein ◽  
Granule Membrane ◽  
Osmotic Lysis ◽  
Per Se ◽  
Chemical Evidence

Exocytosis is a general concept describing secretion of enzymes, hormones and transmitters that are otherwise sequestered in intracellular granules. Chemical evidence for this concept was first gathered from studies on chromaffin cells in perfused adrenal glands, in which it was found that granule contents, including both large protein and small molecules such as adrenaline and ATP, were released together while the granule membrane was retained in the cell. A number of exhaustive reviews of this early work have been published and are summarized in Reference 1. The critical experiments demonstrating the importance of extracellular calcium for exocytosis per se were also first performed in this system (2,3), further indicating the substantial service given by chromaffin cells to those interested in secretory phenomena over the years.

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