37 research outputs found
A Dual Lewis Base Activation Strategy for Enantioselective Carbene-Catalyzed Annulations
A dual activation strategy integrating
N-heterocyclic carbene (NHC)
catalysis and a second Lewis base has been developed. NHC-bound homoenolate
equivalents derived from α,β-unsaturated aldehydes combine
with transient reactive <i>o</i>-quinone methides in an
enantioselective formal [4 + 3] fashion to access 2-benzoxopinones.
The overall approach provides a general blueprint for the integration
of carbene catalysis with additional Lewis base activation modes
A Dual Lewis Base Activation Strategy for Enantioselective Carbene-Catalyzed Annulations
A dual activation strategy integrating
N-heterocyclic carbene (NHC)
catalysis and a second Lewis base has been developed. NHC-bound homoenolate
equivalents derived from α,β-unsaturated aldehydes combine
with transient reactive <i>o</i>-quinone methides in an
enantioselective formal [4 + 3] fashion to access 2-benzoxopinones.
The overall approach provides a general blueprint for the integration
of carbene catalysis with additional Lewis base activation modes
A Dual Lewis Base Activation Strategy for Enantioselective Carbene-Catalyzed Annulations
A dual activation strategy integrating
N-heterocyclic carbene (NHC)
catalysis and a second Lewis base has been developed. NHC-bound homoenolate
equivalents derived from α,β-unsaturated aldehydes combine
with transient reactive <i>o</i>-quinone methides in an
enantioselective formal [4 + 3] fashion to access 2-benzoxopinones.
The overall approach provides a general blueprint for the integration
of carbene catalysis with additional Lewis base activation modes
A Dual Lewis Base Activation Strategy for Enantioselective Carbene-Catalyzed Annulations
A dual activation strategy integrating
N-heterocyclic carbene (NHC)
catalysis and a second Lewis base has been developed. NHC-bound homoenolate
equivalents derived from α,β-unsaturated aldehydes combine
with transient reactive <i>o</i>-quinone methides in an
enantioselective formal [4 + 3] fashion to access 2-benzoxopinones.
The overall approach provides a general blueprint for the integration
of carbene catalysis with additional Lewis base activation modes
A Dual Lewis Base Activation Strategy for Enantioselective Carbene-Catalyzed Annulations
A dual activation strategy integrating
N-heterocyclic carbene (NHC)
catalysis and a second Lewis base has been developed. NHC-bound homoenolate
equivalents derived from α,β-unsaturated aldehydes combine
with transient reactive <i>o</i>-quinone methides in an
enantioselective formal [4 + 3] fashion to access 2-benzoxopinones.
The overall approach provides a general blueprint for the integration
of carbene catalysis with additional Lewis base activation modes
A Dual Lewis Base Activation Strategy for Enantioselective Carbene-Catalyzed Annulations
A dual activation strategy integrating
N-heterocyclic carbene (NHC)
catalysis and a second Lewis base has been developed. NHC-bound homoenolate
equivalents derived from α,β-unsaturated aldehydes combine
with transient reactive <i>o</i>-quinone methides in an
enantioselective formal [4 + 3] fashion to access 2-benzoxopinones.
The overall approach provides a general blueprint for the integration
of carbene catalysis with additional Lewis base activation modes
A Biomimetic Strategy to Access the Silybins: Total Synthesis of (−)-Isosilybin A
We report the first asymmetric, total
synthesis of (−)-isosilybin
A. A late-stage catalytic biomimetic cyclization of a highly functionalized
chalcone is employed to form the characteristic benzopyranone ring.
A robust and flexible approach to this chalcone provides an entry
to the preparation of the entire isomeric family of silybin natural
products
An Enantioselective Cross-Dehydrogenative Coupling Catalysis Approach to Substituted Tetrahydropyrans
An enantioselective
cross-dehydrogenative coupling (CDC) reaction
to access tetrahydropyrans has been developed. This process combines <i>in situ</i> Lewis acid activation of a nucleophile in concert
with the oxidative formation of a transient oxocarbenium electrophile,
leading to a productive and highly enantioselective CDC. These advances
represent one of the first successful applications of CDC for the
enantioselective couplings of unfunctionalized ethers. This system
provides efficient access to valuable tetrahydropyran motifs found
in many natural products and bioactive small molecules
An Enantioselective Cross-Dehydrogenative Coupling Catalysis Approach to Substituted Tetrahydropyrans
An enantioselective
cross-dehydrogenative coupling (CDC) reaction
to access tetrahydropyrans has been developed. This process combines <i>in situ</i> Lewis acid activation of a nucleophile in concert
with the oxidative formation of a transient oxocarbenium electrophile,
leading to a productive and highly enantioselective CDC. These advances
represent one of the first successful applications of CDC for the
enantioselective couplings of unfunctionalized ethers. This system
provides efficient access to valuable tetrahydropyran motifs found
in many natural products and bioactive small molecules
Lewis Acid Activation of a Hydrogen Bond Donor Metal–Organic Framework for Catalysis
A new metal–organic
framework (MOF) composed of urea-containing
tetracarboxylate struts was synthesized, and its hydrogen bonding
capabilities were evaluated. The catalytic performance of this heterogeneous
framework is enhanced through preactivation with silyl Lewis acids,
leading to Friedel–Crafts reaction rates greater than those
of common homogeneous hydrogen bond donors