Rhodium(I)-Catalyzed CO-Gas-Free Arylative Dual-Carbonylation of Alkynes with Arylboronic Acids via the Formyl C–H Activation of Formaldehyde

Synthesis ◽

10.1055/a-1468-8377 ◽

2021 ◽

Author(s):

Tsumoru Morimoto ◽

Chuang Wang ◽

Hiroki Tanimoto ◽

Levent Artok ◽

Kiyomi Kakiuchi

Keyword(s):

Arylboronic Acids ◽

Simultaneous Loading ◽

Co Gas

AbstractThe rhodium(I)-catalyzed reaction of alkynes with arylboronic acids in the presence of formaldehyde results in a CO-gas-free arylative dual-carbonylation to produce γ-butenolide derivatives. The simultaneous loading of phosphine-ligated and phosphine-free rhodium(I) complexes is required for efficient catalysis. The former complex catalyzes the abstraction of a carbonyl moiety from formaldehyde through the activation of its formyl C–H bond (decarbonylation) and the latter catalyzes the subsequent dual-incorporation of the resulting carbonyl unit (carbonylation). The use of larger amounts of the phosphine-ligated rhodium(I) complex generates more carbonyl units, leading to the formation γ-butenolides via the dual-incorporation of the carbonyl unit.

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384. Evaluation of Commercial Electrochemical CO Gas Monitors

10.3320/1.2765063 ◽

1999 ◽

Author(s):

S. Wang ◽

H. Chein ◽

D. Tang ◽

J. Yu

Keyword(s):

Co Gas

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Reductive Hexamerization of CO Involving Cooperativity Between Magnesium(I) Reductants and [Mo(CO)6]: Synthesis of Well-Defined Magnesium Benzenehexolate Complexes

10.26434/chemrxiv.12780428 ◽

2020 ◽

Author(s):

Albert Paparo ◽

K. Yuvaraj ◽

Aidan J. R. Matthews ◽

Iskander Douair ◽

Laurent Maron ◽

...

Keyword(s):

Unknown Mechanism ◽

Co Gas

The first examples of magnesium benzenehexolate complexes are prepared by reductive hexamerizations of CO, in reactions that are initiated (or catalyzed) by [Mo(CO)6]. These reactions are closely related to Justus von Liebig’s classical 1834 study on the reduction of CO gas with molten potassium, which yields K6C6O6 (amongst other products), by an as yet unknown mechanism.

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Arylboronic Acids in Self-condensation of Glucosamines Forming Deoxyfructosazine, Catalysts or Reagents?

10.26434/chemrxiv.7528376 ◽

2019 ◽

Author(s):

Meifeng Wang ◽

Gan Zhu ◽

Yiqun Li ◽

Liuqun Gu

Keyword(s):

Molecular Recognition ◽

Boric Acid ◽

Boronic Acid ◽

Catalytic Mechanism ◽

Organic Transformations ◽

Food Industries ◽

Arylboronic Acids ◽

Excess Amount ◽

Phenyl Boronic Acid ◽

Boron Acid

Arylboronic acids were widely used as efficient catalysts in direct amide formation and other organic transformations. Surprisingly, reports on their use as catalysts in carbohydrates synthesis are very rare even though boron acid-diol complexation was extensively investigated in molecular recognition for saccharides and so on. Here we developed an efficient arylboronic acids catalyzed dimerization of glucosamines forming deoxyfructosazine which is important compound in pharmaceutical and food industries, against a commonly held belief that excess amount of phenyl boronic acid (or boric acid) is a must. A catalytic mechanism was also proposed and arylboronic acids instead of their boronates was identified as catalysts.

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ANALISIS PENGUKURAN KONSENTRASI KARBONMONOKSIDA (CO) PADA BREATHING ZONE PETUGAS PARKIR BASEMENT MALL KOTA BANDUNG

10.31219/osf.io/6p4zm ◽

2019 ◽

Author(s):

Gede H Cahyana

Keyword(s):

Air Pollution ◽

Indoor Air ◽

Indoor Air Pollution ◽

Sampling Method ◽

Breathing Zone ◽

Gas Concentration ◽

Average Value ◽

Co Concentration ◽

Personal Dosimeter ◽

Co Gas

Indoor air pollution in closed room is one of the air pollution that gives serious threats to human health. One of them come from vehicle gas emissions in closed parking area. This research identifies and analyses CO concentration measured in Mall X parking man’s breathing zone with closed parking area and in Mall Y semi-opened parking area. CO measurement carried out by passive sampling method using Personal Dosimeter Tubes. Measurement result of CO gas concentration to parking man’s breathing zone in Mall X was 25 – 81,25 ppm with average value in 50 ± 26,15 ppm. Meanwhile CO gas concentration in Mall Y gave result 3,13 – 12,5 ppm with average value in 7,88 ± 4,36 ppm. Correlation value between CO concentration and its intake in Mall X area was 0,9983, meanwhile correlation value between CO concentration and its intake in Mall Y area was 0,9903. It was concluded that CO gas concentration measured in parking man’s breathing zone influenced the differences of CO intake value in significance value.

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