分子定义的手性boxmi铁烷基络合物催化各种官能化酮的氢硼化,并提供相应的手性卤代醇,氧杂杂环(环氧乙烷,氧杂环丁烷,四氢呋喃和二恶烷)和氨基醇,具有出色的对映选择性(高达> 99%ee)和转化效率在低催化剂负载量(低至0.5 mol%)下。在−30°C时,周转频率大于40000 h -1突显了这种富含地球的金属催化剂的活性,该催化剂可耐受许多官能团。
Site- and Enantiodifferentiating C(sp<sup>3</sup>)–H Oxidation Enables Asymmetric Access to Structurally and Stereochemically Diverse Saturated Cyclic Ethers
作者:Shutao Sun、Yiying Yang、Ran Zhao、Dongju Zhang、Lei Liu
DOI:10.1021/jacs.0c09636
日期:2020.11.11
A manganese-catalyzed site- and enantiodifferentiating oxidation of C(sp3)-H bonds in saturated cyclic ethers has been described. The mild and practical method is applicable to a range of tetrahydrofurans, tetrahydropyrans, and medium-sized cyclic ethers with multiple stereocenters and diverse substituent patterns in high efficiency with extremely efficient site- and enantiodiscrimination. Late-stage
Cyclic ethers have been effectively synthesized via the intramolecular cyclization of diols using trimethyl phosphate and NaH. The present cyclization could proceed at room temperature to produce 5–7 membered cyclic ethers in good to excellent yields. Substrates possessing a chiral secondary hydroxy group were transformed into the corresponding chiral cyclic ethers along with the retention of their
Intramolecular Displacement of Phenylselenone by a Hydroxy Group: Stereoselective Synthesis of 2-Substituted Tetrahydrofurans
作者:Lucio Minuti、Anna Barattucci、Paola Maria Bonaccorsi、Maria Luisa Di Gioia、Antonella Leggio、Carlo Siciliano、Andrea Temperini
DOI:10.1021/ol401653w
日期:2013.8.2
An efficient and stereocontrolled synthesis of 2-substituted tetrahydrofurans has been achieved. The approach employs the asymmetric reduction of γ-phenylseleno ketones obtained by three different procedures that are peculiarly applied to the synthesis of such compounds. Finally, the intramolecular substitution of the phenylselenone residue by the oxygen atom of a hydroxy group gives the tetrahydrofuran
One-Pot Asymmetric Synthesis of 2- and 2,3-Disubstituted Tetrahydrofuran Derivatives
作者:P. Veeraraghavan Ramachandran、Hari N. G. Nair、Pravin D. Gagare
DOI:10.1021/jo300414u
日期:2012.6.15
A novel and convenient one-pot asymmetric synthesis of 2- and 2,3-disubstituted tetrahydrofurans has been achieved in 56-81% yields and 86-99% ee from aliphatic and aromatic aldehydes via an allyl/crotyl/alkoxyallylboration-hydroboration-iodination-cyclization reaction sequence.