Catalytic Asymmetric Synthesis of Geminal-Dicarboxylates

20 April 2018, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

Stereogenic acetals, spiroacetals and ketals are well-studied stereochemical features that bear two heteroatoms at a common carbon atom. These stereocenters are normally found in cyclic structures while linear (or acyclic) analogues bearing two heteroatoms are rare. Chiral geminal-dicarboxylates are illustrative, there is no current way to access this class of compounds while controlling the stereochemistry at the carbon center bound to two oxygen atoms. Here we report a rhodium-catalyzed asymmetric carboxylation of ester-containing allylic bromides to form stereogenic carbon centers bearing two different carboxylates with high yields and enantioselectivities. The products, which are surprisingly stable to a variety of acidic and basic conditions, can be manipulated with no loss of enantiomeric purity as demonstrated be ring closing metathesis reactions to form chiral lactones, which have been extensively used as building blocks in asymmetric synthesis.

Keywords

Rhodium
Catalysis
gem-dicarboxylates
allylic substitution
carboxylation

Supplementary materials

Title
Description
Actions
Title
Dicarboxylate SI
Description
Actions

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