Substitution of Secondary Propargylic Phosphates Using Aryl-Lithium-Based Copper Reagents
نویسندگان
چکیده
The substitution of secondary propargylic phosphates ROP(O)(OEt)2 where R = [Ph(CH2)2]C(H)(C≡CTMS)] Ph(CH2)2CH(OP(O)(OEt)2)(C≡CTMS) with copper reagents derived from PhLi and salts such as CuCl, CuCN, Cu(acac)2 was studied to establish an ArLi-based reagent system. Among the prepared, PhLi/CuCl (2:1) showed 98% α regioselectivity (rs), while PhLi/Cu(acac)2 γ selective (>99% rs). prepared in situ PhI PhBr by Li-halogen exchange t-BuLi also used for substitution. A study using (S)-phosphate disclosed 99% enantiospecificity (es) inversion stereochemistry. five substituted aryl produced corresponding products high rs es values. Similar reactivity selectivity were observed 2-furyl 2-thienyl reagents, which via direct lithiation n-BuLi.
منابع مشابه
Copper-catalyzed asymmetric allylic substitution with aryl and ethyl Grignard reagents.
Phenyl- and ethyl-magnesium bromides undergo regioselective asymmetric allylic substitution with high enantioselectivity under the catalysis of chiral amidophosphane-copper(I) complexes.
متن کاملHighly enantioselective copper-catalyzed propargylic substitution of propargylic acetates with 1,3-dicarbonyl compounds.
A chiral tridentate ketimine P,N,N-ligand has been successfully applied in the copper-catalyzed enantioselective propargylic substitution of propargylic acetates with a variety of β-dicarbonyl compounds, in which excellent enantioselectivities (up to >99% ee) and high yields have been obtained.
متن کاملCopper-catalyzed propargylic substitution of dichloro substrates: enantioselective synthesis of trisubstituted allenes and formation of propargylic quaternary stereogenic centers.
An easy and versatile Cu-catalyzed propargylic substitution process is presented. Using easily prepared prochiral dichloro substrates, readily available Grignard reagents together with catalytic amount of copper salt and chiral ligand, we accessed a range of synthetically interesting trisubstituted chloroallenes. Substrate scope and nucleophile scope are broad, providing generally high enantios...
متن کاملSynthesis of highly substituted allylic alcohols by a regio- and stereo-defined CuCl-mediated carbometallation reaction of 3-aryl-substituted secondary propargylic alcohols with Grignard reagents.
A highly regio- and stereoselective CuCl-mediated carbometallation reaction of 3-aryl-substituted secondary propargylic alcohols with alkyl, aryl, vinyl or allyl Grignard reagents for the synthesis of fully-substituted allylic alcohols was developed. The R(2) group from the Grignard reagent was successfully introduced to the 2-position of the propargylic alcohols due to the chelation of metal a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Catalysts
سال: 2023
ISSN: ['2073-4344']
DOI: https://doi.org/10.3390/catal13071084