Asymmetric Transfer Hydrogenation of <i>o</i>-Hydroxyphenyl Ketones: Utilizing Directing Effects That Optimize the Asymmetric Synthesis of Challenging Alcohols
作者:Ye Zheng、Guy J. Clarkson、Martin Wills
DOI:10.1021/acs.orglett.0c01213
日期:2020.5.1
A systematic range of o-hydroxyphenyl ketones were reduced under asymmetrictransferhydrogenation conditions using the C3-tethered catalyst 2. Two directing effects, i.e., an o-hydroxyphenyl coupled to a bulky aromatic on the opposite side of the ketone substrate, combine in a matched manner to deliver reduction products with very high enantiomeric excess.
Amino Acid‐Functionalized Metal‐Organic Frameworks for Asymmetric Base–Metal Catalysis
作者:Rajashree Newar、Naved Akhtar、Neha Antil、Ajay Kumar、Sakshi Shukla、Wahida Begum、Kuntal Manna
DOI:10.1002/anie.202100643
日期:2021.5.3
We report a strategy to develop heterogeneous single‐site enantioselective catalysts based on naturally occurring aminoacids and earth‐abundant metals for eco‐friendly asymmetric catalysis. The grafting of aminoacids within the pores of a metal‐organic framework (MOF), followed by post‐synthetic metalation with iron precursor, affords highly active and enantioselective (>99 % ee for 10 examples)
Asymmetric reduction of ortho-substituted benzophenones with B-chlorodiisopinocampheylborane: A convenient synthesis of enantiomerically enriched benzhydrols
作者:Wen-Chung Shieh、William R. Cantrell、John A. Carlson
DOI:10.1016/0040-4039(95)00609-g
日期:1995.5
A very efficient synthesis of chiral benzhydrols from ortho-substituted benzophenones is described which presumably utilizes a heteroatom-directed, intramolecular asymmetricreduction of ketones with B-chlorodiisopinocampheylborane.
The synthesis of diarylmethanols via the reduction of a range of substituted benzophenone and benzoylpyridine derivatives with ketoreductase enzymes (KREDs) has afforded chiral products with high yield (>90%) and ee (up to >99%). Ortho, meta, and para substitutions with a variety of electron-donating, electron-withdrawing, and halogen groups were examined. Substitution at the ortho position and/or
An enantiopure galactose oxidase model: synthesis of chiral amino alcohols through oxidative kinetic resolution catalyzed by a chiral copper complex
作者:Sreedevi Mannam、Govindasamy Sekar
DOI:10.1016/j.tetasy.2009.02.013
日期:2009.3
An enantiopure galactoseoxidase (GO) enzyme model has been synthesized from readily available (R)-BINAM and Cu(OTf)2, and the enantiopure GO model has been effectively used in situ as an efficient chiral catalyst for the synthesis of chiral amino alcohols through oxidative kinetic resolution (OKR), where molecular oxygen is used as the sole oxidant. Under the proposed catalytic conditions, both ortho-