Ligand-enabled Ir-catalyzed intermolecular diastereoselective and enantioselective allylic alkylation of 3-substituted indoles

Chemical Science, Journal Year: 2015, Volume and Issue: 6(8), P. 4525 - 4529

Published: Jan. 1, 2015

A ligand-enabled Ir-catalyzed diastereoselective and enantioselective allylic alkylation of 3-substituted indoles is reported, providing indoline products containing three contiguous stereocenters in one step with high site-, regio-, diastereo- enantioselectivities from a wide range readily available starting materials.

Language: Английский

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Synthesis of Enantioenriched Vicinal Tertiary and Quaternary Carbon Stereogenic Centers within an Acyclic Chain

Angewandte Chemie International Edition, Journal Year: 2019, Volume and Issue: 59(1), P. 36 - 49

Published: May 13, 2019

Abstract Overcoming the inherent difficulty to prepare quaternary carbon stereogenic centers, diastereo‐ and enantioselective preparation of acyclic backbones possessing vicinal tertiary centers (i.e. in a 1,2‐relationship) causes distorted geometries represents very acute problem organic synthesis. Several approaches are discussed this minireview underlining challenges illustrated by rather limited number available practitioners.

Language: Английский

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Stereospecific Cross Couplings To Set Benzylic, All-Carbon Quaternary Stereocenters in High Enantiopurity

Journal of the American Chemical Society, Journal Year: 2016, Volume and Issue: 138(37), P. 12057 - 12060

Published: Sept. 9, 2016

Asymmetric preparation of all-carbon quaternary stereocenters is an important goal. Despite advances in formation highly enantioenriched products with proximal to a functional group, methods install isolated from groups are limited. Transition metal catalysis offers potential solution, but prior cross couplings limited allylic substrates or deliver little no enantiomeric enrichment. We report stereospecific, nickel-catalyzed Suzuki–Miyaura arylation tertiary benzylic acetates diaryl and triaryl high yields ee's. This reaction employs inexpensive, air-stable Ni(II) salt commercially available phosphine ligand transform alcohol derivatives, which easily exceptional ee, into valuable stereoretention.

Language: Английский

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Congested C–C Bonds by Pd-Catalyzed Enantioselective Allyl–Allyl Cross-Coupling, a Mechanism-Guided Solution

Journal of the American Chemical Society, Journal Year: 2014, Volume and Issue: 136(19), P. 7092 - 7100

Published: April 11, 2014

Under the influence of a chiral bidentate diphosphine ligand, Pd-catalyzed asymmetric cross-coupling allylboron reagents and allylic electrophiles establishes 1,5-dienes with adjacent stereocenters in high regio- stereoselectivity. A mechanistic study coupling utilizing reaction calorimetry density functional theory analysis suggests that operates through an inner-sphere 3,3'-reductive elimination pathway, which is both rate-defining stereodefining. Coupled optimized conditions, this detail used to expand scope allyl-allyl couplings allow generation tertiary centers quaternary as well unique set cyclic structures.

Language: Английский

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Enantioselective Formation of CF₃-Bearing All-Carbon Quaternary Stereocenters via C–H Functionalization of Methanol: Iridium Catalyzed Allene Hydrohydroxymethylation

Journal of the American Chemical Society, Journal Year: 2017, Volume and Issue: 139(24), P. 8114 - 8117

Published: June 12, 2017

Using an iridium catalyst modified by PhanePhos, CF3-allenes react with methanol to form branched products of hydrohydroxymethylation as single regioisomers excellent levels enantiomeric enrichment. This hydrogen autotransfer process enables catalytic enantioselective formation acyclic CF3-bearing all-carbon quaternary stereocenters in the absence stoichiometric metals or byproducts.

Language: Английский

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