Halides as versatile anions in asymmetric anion-binding organocatalysis

• Lukas Schifferer,
• Martin Stinglhamer,
• Kirandeep Kaur and
• Olga García Macheño

Beilstein J. Org. Chem. 2021, 17, 2270–2286, doi:10.3762/bjoc.17.145

• focus has also been turned to the development of other catalyst systems that are not based on N–H bonds, such as the chiral silanediol catalysts first reported by Mattson and co-workers in 2013 [19][20]. Furthermore, it is worthy to mention that in parallel to the investigations towards new chiral

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

• Falco Fox,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

• , BIFOXSiCl2) is synthesized and employed as precursor for the new silanols biphenyl-2,2’-bisfenchyloxychlorosilanol (8, BIFOXSiCl(OH)) and biphenyl-2,2’-bisfenchyloxysilanediol (9, BIFOXSi(OH)2). BIFOXSiCl2 (7) shows a remarkable stability against hydrolysis, yielding silanediol 9 under enforced conditions. A

• kcal mol−1) and BIFOXSiCl(OH) (8) to BIFOXSi(OH)2 (9, Ea = 31.4 kcal mol−1) with high activation barriers, enforced by endo fenchone units. Crystal structure analyses of silanediol 9 with acetone show shorter hydrogen bonds between the Si–OH groups and the oxygen of the bound acetone (OH···O 1.88(3

• )–2.05(2) Å) than with chlorosilanol 8 (OH···2.16(0) Å). Due to its two hydroxy units, the silanediol 9 shows higher catalytic activity as hydrogen bond donor than chlorosilanol 8, e.g., C–C coupling N-acyl Mannich reaction of silyl ketene acetals 11 with N-acylisoquinolinium ions (up to 85% yield and 12

Synthesis, spectral characterization, electron microscopic study and thermogravimetric analysis of a phosphorus containing dendrimer with diphenylsilanediol as core unit

• E. Dadapeer,
• B. Hari Babu,
• C. Suresh Reddy and
• Naga Raju Charmarthi

Beilstein J. Org. Chem. 2010, 6, 726–731, doi:10.3762/bjoc.6.85

• on the final dendritic molecule. Keywords: diphenyl silanediol; divergent method; phosphorus containing dendrimer; scanning electron microscopy; Schiff’s base; thermogravimetric analysis; Introduction Dendrimers constitute a new class of macromolecules that can offer a potentially defect-free

• . Results and Discussion Scheme 1 and Scheme 2 summarise the preparation of the dendrimer G6 with diphenyl silanediol as the core unit. The first step of this synthesis is a condensation reaction between diphenyl silanol and POCl3 in the presence of triethylamine at 0 to −15 °C to afford the product G1. In