Acid–Base Reactions of π-Bonds: Addition Reactions

2016 ◽  
pp. 359-422
Keyword(s):  
Addition Reactions ◽  
Acid Base

scholarly journals Neutral, cationic and anionic organonickel and -palladium complexes supported by iminophosphine/phosphinoenaminato ligands

2020 ◽  
Vol 49 (2) ◽  
pp. 322-335 ◽  
Author(s):  
Tomás G. Santiago ◽  
Carmen Urbaneja ◽  
Eleuterio Álvarez ◽  
Elena Ávila ◽  
Pilar Palma ◽  
...  
Keyword(s):  
Ligand Exchange ◽  
Oxidative Addition ◽  
Palladium Complexes ◽  
Addition Reactions ◽  
Acid Base

Ligand exchange and oxidative addition reactions allow the synthesis of Ni(ii) and Pd(ii) complexes with deprotonable iminophosphine ligands. The acid–base behavior of iminophosphine ligands coordinated to organometallic Ni(ii) fragments is analyzed.

scholarly journals Lewis acid–base 1,2-addition reactions: synthesis of pyrylium borates from en-ynoate precursors

2016 ◽  
Vol 45 (14) ◽  
pp. 5929-5932 ◽  
Author(s):  
Lewis C. Wilkins ◽  
Hugh B. Hamilton ◽  
Benson M. Kariuki ◽  
A. Stephen K. Hashmi ◽  
Max M. Hansmann ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Addition Reactions ◽  
Acid Base ◽  
Strong Lewis Acid

Treatment of methyl (Z)-2-alken-4-ynoates with the strong Lewis acid tris(pentafluorophenyl) borane, B(C6F5)3, yield 2,5,6-substituted zwitterionic pyrylium borate species via an intramolecular 6-endo-dig cyclisation reaction.

Coordination Chemistry of N,N′-Bis(diphenylphosphanylmethyl)- 2,3-dihydro-1H-perimidine – Lewis Acid-Base Complexes with the d10-Metals Nickel(0) and Gold(I)

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1299-1305 ◽  
Author(s):  
Sven Krieck ◽  
Daniel Schulze ◽  
Helmar Görls ◽  
Matthias Westerhausen
Keyword(s):  
Coordination Chemistry ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Lewis Acid ◽  
Nickel Complexes ◽  
Nickel Atom ◽  
Addition Reactions ◽  
Acid Base ◽  
Tetrahedral Environment

Abstract The addition reactions of N,N′-bis(diphenylphosphanylmethyl)-2,3-dihydro-1H-perimidine (1) with [(cod)2Ni] and [(Ph3P)AuCl] yield yellow [(1)Ni(η4-cod)] (2) and colorless [(1)(Ph3P)AuCl]·3MeOH (3), respectively. In these transition metal complexes of nickel(0) and gold(I) 1 acts as a bidentate chelating ligand. Crystal structures of [(1)Ni(η4-cod)]·3THF (2a) and of cosolvent-free [(1)Ni(η4-cod)] (2) reveal a distorted tetrahedral environment of the nickel atom. The gold(I) atom in 3 exhibits a very long Au-Cl bond of 296.2(1) pm. In contrast to the nickel complexes, compound 3 shows strong agostic interactions between gold(I) and a methylene fragment.

Acid-Base Bifunctional Catalytic Surfaces for Nucleophilic Addition Reactions

2008 ◽  
Vol 3 (8-9) ◽  
pp. 1230-1236 ◽  
Author(s):  
Ken Motokura ◽  
Mizuki Tada ◽  
Yasuhiro Iwasawa
Keyword(s):  
Nucleophilic Addition ◽  
Addition Reactions ◽  
Acid Base ◽  
Catalytic Surfaces

Higher Dietary Acidity is Associated with Lower Bone Mineral Density in Postmenopausal Iranian Women, Independent of Dietary Calcium Intake

2014 ◽  
Vol 84 (3-4) ◽  
pp. 0206-0217 ◽  
Author(s):  
Seyedeh-Elaheh Shariati-Bafghi ◽  
Elaheh Nosrat-Mirshekarlou ◽  
Mohsen Karamati ◽  
Bahram Rashidkhani
Keyword(s):  
Calcium Intake ◽  
Dietary Calcium ◽  
Dietary Calcium Intake ◽  
Dietary Intakes ◽  
Iranian Women ◽  
Acid Base Balance ◽  
Mineral Density ◽  
Acid Base ◽  
Base Balance ◽  
Dietary Acid

Findings of studies on the link between dietary acid-base balance and bone mass are relatively mixed. We examined the association between dietary acid-base balance and bone mineral density (BMD) in a sample of Iranian women, hypothesizing that a higher dietary acidity would be inversely associated with BMD, even when dietary calcium intake is adequate. In this cross-sectional study, lumbar spine and femoral neck BMDs of 151 postmenopausal women aged 50 - 85 years were measured using dual-energy x-ray absorptiometry. Dietary intakes were assessed using a validated food frequency questionnaire. Renal net acid excretion (RNAE), an estimate of acid-base balance, was then calculated indirectly from the diet using the formulae of Remer (based on dietary intakes of protein, phosphorus, potassium, and magnesium; RNAERemer) and Frassetto (based on dietary intakes of protein and potassium; RNAEFrassetto), and was energy adjusted by the residual method. After adjusting for potential confounders, multivariable adjusted means of the lumbar spine BMD of women in the highest tertiles of RNAERemer and RNAEFrassetto were significantly lower than those in the lowest tertiles (for RNAERemer: mean difference -0.084 g/cm2; P=0.007 and for RNAEFrassetto: mean difference - 0.088 g/cm2; P=0.004). Similar results were observed in a subgroup analysis of subjects with dietary calcium intake of >800 mg/day. In conclusion, a higher RNAE (i. e. more dietary acidity), which is associated with greater intake of acid-generating foods and lower intake of alkali-generating foods, may be involved in deteriorating the bone health of postmenopausal Iranian women, even in the context of adequate dietary calcium intake.

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