Substituent effect of camphor sulfonamide ligand on the asymmetric addition of diethylzinc to aldehyde

Hui, Ailing; Zhang, Jin-Tang; Wang, Zhiyong

doi:10.3998/ark.5550190.0007.d05

Cited by 5 publications

(2 citation statements)

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“…The yields were high in most cases, and ligands 1 could be isolated by column chromatography, the related endoalcohol being the only byproduct. [14][15][16] Once ligands 1 had been prepared, they were tested in the enantioselective addition of diethylzinc (4a) to benzaldehyde (3a) and gave the expected secondary alcohol 5a in practically quantitative yields as is depicted in Table 2.…”

Section: Enantioselective Addition Of Organozinc Reagents To Aldehydesmentioning

confidence: 99%

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Chiral Ligands with an Isoborneol-10-sulfonamide Structure: A Ten-Year Odyssey

Ramón¹,

Yus²

2007

Synlett

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C h i r a l L i g a n d s w i t h a n I s o b o r n e o l -1 0 -s u l f o n a m i d e S t r u c t u r e : A T e n -Y e a r O d y s s e y Abstract: The isoborneol-10-sulfonamide unit represents a new type of chiral structure that has been successfully prepared and used in different reactions of organometallic addition to aldehydes and ketones. The obtained results were excellent in some cases, and this type of ligand is unique as it is able to promote the enantioselective addition of dialkylzinc reagents to simple ketones. The scope of these catalyzed reactions, together with some synthetic applications, is outlined. References to important related work from others are also included.

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Section: Enantioselective Addition Of Organozinc Reagents To Aldehydesmentioning

confidence: 99%

“…Substitution on the aromatic ring of the aniline moiety did not produce any advantage (Table 2, entries 5-8). 15 Finally, it should be noted that the presence of an extra coordinating functionality, such as in ligand 1i, 16 had an important detrimental effect.…”

Section: Enantioselective Addition Of Organozinc Reagents To Aldehydesmentioning

confidence: 99%

Chiral Ligands with an Isoborneol-10-sulfonamide Structure: A Ten-Year Odyssey

Ramón¹,

Yus²

2007

Synlett

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The Syntheses of new Camphorsulfonylated Ligands Derived from 2‐Amino‐2′‐Hydroxy‐1,1′‐Binaphthyl and Their Enantioselectivities in the Addition of Dialkylzinc Reagents to Aldehydes

et al. 2012

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A series of new camphorsulfonylated ligands derived from chiral 2-amino-2'-hydroxy-1,1'-binaphthyl (NOBIN) and (+)-camphorsulfonic acid were synthesized by a short and simple synthetic sequence, and their enantioselective catalytic activities were assessed in the nucleophilic addition reaction of dialkylzinc reagents to aldehydes in the presence of titanium tetraisopropoxide. The most efficient ligand, N-hydroxycamphorsulfonylated (S)-NOBIN, gave (S)-addition products with good yields and up to 87% of ee value. The (1)H nuclear magnetic resonance (NMR) and (13)C NMR results of the titanium titration experiments on this ligand indicate that the most likely catalytic reactive species involved in this catalytic asymmetric addition is a bimetallic titanium complex. A possible catalytic reaction mechanism is proposed.

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