The asymmetric Michael reaction of methyl alkynyl ketone and α,β-unsaturated aldehyde catalyzed by diphenylprolinol silyl ether was developed. Although methyl alkynyl ketone is a good Michael acceptor, it also acts as a Michael donor to afford the synthetically important δ-oxo aldehydes with excellent enantioselectivity. The products possessing several functional groups, such as alkyne, ketone, and aldehyde moieties, are useful chiral building blocks for further synthesis. Using this reaction as a key step, a side chain of atorvastatin (Lipitor), an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, was synthesized in a two-pot sequence with excellent diastereo- and enantioselectivities.
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http://dx.doi.org/10.1021/acsorginorgau.1c00054 | DOI Listing |
J Am Chem Soc
January 2025
Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Chemistry
November 2024
Frontiers Science Center for Transformative Molecules, Zhangjiang Institute for Advanced Study, and Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
The daunting challenges in converting alcoholic O-H bonds with high bond-dissociation energy (BDE) to alkoxy radicals and harnessing those unruly reaction species largely limit exploiting free alcohols in C(sp)-H functionalization. Herein we describe a novel radical alkynylation and allylation of unactivated C(sp)-H bonds with unmodified aliphatic alcohols. The use of phenyliodine bis(trifluoroacetate) (PIFA) enables the formation of alkoxy radicals under mild photochemical conditions.
View Article and Find Full Text PDFJ Am Chem Soc
October 2024
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K.
Polyanionic antisense oligonucleotides hold great promise as RNA targeting drugs but issues with bioavailability hinder their development. Uncharged phosphorus-based backbones are promising alternatives but robust methods to produce them are limited. We report the synthesis and properties of oligonucleotides containing charge-neutral LNA alkyl phosphothiotriester backbones combined with 2'--methyl phosphorothioate nucleotides for therapeutic applications.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2024
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34 Street, Philadelphia, Pennsylvania 19104-6323, USA.
J Org Chem
October 2024
College of Chemistry, International Phosphorus Laboratory, Zhengzhou University, Zhengzhou 450001, China.
New reactions of benzyl phosphine oxide/sulfide with oxalyl chloride are presented. The resulting reactive intermediates, acyl chloride-substituted chlorophosphonium ylides, are capable of undergoing esterification and Friedel-Crafts acylation reactions, ultimately yielding either methyl 2-(2-bromophenyl)-2-(diphenylphosphoryl)acetate or β-carbonyl-diarylphosphine oxide derivatives. Additionally, when an alkynyl group is contained in the acyl chloride-substituted chlorophosphonium ylide, intramolecular cyclization occurs, leading to the formation of a pair of and dichlorophosphonyl benzofulvene isomers.
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