Chemo- and Enantioselective Addition and β-Hydrogen Transfer Reduction of Carbonyl Compounds with Diethylzinc Reagent in One Pot Catalyzed by a Single Chiral Organometallic Catalyst

A series of enantiopure ( R )-adamantyl 1,1′-binaphthalene-2,2′-diols were successfully synthesized in a straightforward one-step reaction from commercial products with excellent overall yields. The activity of chiral titanium catalyst derived from ( R )-3,6,6′-tri(adamantan-1-yl)-[1,1′-binaphthalene]-2,2′-diol ligand, ( R )-(2)-Ti , in the enantioselective asymmetric alkylation of aldehydes is significantly enhanced (up to 98% yield and 99% ee).

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“…dAbsolute configuration was assigned by comparison with the product known from the literature. 13,14 …”

Section: Resultsmentioning

confidence: 99%

“… a Reaction conditions: BINOL/[Ti]/aldehyde/Et 2 Zn (0.1/1.4/1.0/3.0). b Reaction time: 30 min. Yield determined by GC in the presence of dodecane as the internal reference. c Measured by GC using a CP-Chirasil-Dex chiral column. d Absolute configuration was assigned by comparison with the product known from the literature. , …”

Section: Resultsmentioning

confidence: 99%

Readily Available Highly Active [Ti]-Adamantyl-BINOL Catalysts for the Enantioselective Alkylation of Aldehydes

et al. 2018

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“…Earlier in 2015, Song et al described enantioselective zinccatalyzed domino transfer reduction/ethylation reaction of aryl a-trifluoromethylketones 337, 338 with ZnEt 2 performed in the presence of 30 mol% of chiral 1,2-amino phosphoramide ligand 339 [149]. The process included the asymmetric b-H transfer reduction of the aryl a-trifluoro ketones and the enantioselective addition of ZnEt 2 to the aromatic aldehyde moieties (Scheme 114).…”

Section: Other Domino Reactionsmentioning

confidence: 99%

Recent developments in enantioselective zinc-catalyzed transformations

Pellissier

2021

Coordination Chemistry Reviews

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This review collects the recent advances in the field of enantioselective zinc-catalyzed transformations, covering the literature since the beginning of 2015, illustrating the power of chiral green zinc catalysts to promote all types of reactions. A range of highly enantioselective reactions have been developed in the last six years, including cycloadditions, alkynylation/allylation reactions of carbonyl compounds and derivatives, additions of diorganozincs to carbonyl compounds and derivatives, Mannich reactions, (nitro)aldol reactions, other 1,2-nucleophilic additions to carbonyl compounds and derivatives, Michael additions, Friedel-Crafts reactions, reductions, a-functionalizations of carbonyl compounds, ringopening reactions, epoxidations, halolactonizations, domino/tandem reactions and miscellaneous reactions.

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“…In 2015, Song et al demonstrated that chiral 1,2-amino phosphoramide ligand 110 was efficient in both the asymmetric β-H transfer reduction of aryl α-trifluoromethylketones 111,112 and enantioselective addition of ZnEt 2 of aromatic aldehydes performed in one-pot under the same reaction conditions [67]. As shown in Scheme 30, the corresponding chiral fluorinated diols 113,114 were obtained from the domino transfer reduction/ethylation reaction performed in toluene at -20 °C in the presence of 30 mol% of ligand 110 in high yields (86-90%) with excellent enantioselectivities (92-97% ee) albeit combined with moderate diastereoselectivities (40-42% de).…”

Section: Reactions Using 12-diamine Ligandsmentioning

confidence: 99%