Borylation of Propargylic Substrates by Bimetallic Catalysis. Synthesis of Allenyl, Propargylic, and Butadienyl Bpin Derivatives
نویسندگان
چکیده
منابع مشابه
Borylation of propargylic substrates by bimetallic catalysis. Synthesis of allenyl, propargylic, and butadienyl Bpin derivatives.
Bimetallic Pd/Cu and Pd/Ag catalytic systems were used for borylation of propargylic alcohol derivatives. The substrate scope includes even terminal alkynes. The reactions proceed stererospecifically with formal SN2' pathways to give allenyl boronates. Opening of propargyl epoxides leads to 1,2-diborylated butadienes probably via en allenylboronate intermediate.
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 کاملTransition‐Metal‐Free Borylation of Allylic and Propargylic Alcohols
The base-catalyzed allylic borylation of tertiary allylic alcohols allows the synthesis of 1,1-disubstituted allyl boronates, in moderate to high yield. The unexpected tandem performance of the Lewis acid-base adduct, [Hbase](+) [MeO-B2 pin2 ](-) favored the formation of 1,2,3-triborylated species from the tertiary allylic alcohols and 1-propargylic cyclohexanol at 90 °C.
متن کاملRegioselective synthesis of highly functionalized alkenylboronates by Cu-catalyzed borylation of propargylic silylalkynes.
High regioselectivity was achieved in the Cu(i)-catalyzed borylation of internal propargylic alkynes with a silyl substituent to afford multifunctionalized alkenylboron compounds. While both the silyl and propargylic substituents are known to act as directing groups, a N-heterocyclic carbene (NHC)-Cu complex furnished β-vinylboronate products (relative to Si) with high selectivity.
متن کاملSynthesis of propargylic fluorides from allenylsilanes.
Allenylsilanes reacted at room temperature in acetonitrile with Selectfluor, an electrophilic fluorinating reagent, to give secondary propargylic fluorides in moderate to good yields; mechanistically, a side-product resulting from a 1,2-silyl shift testifies to the presence of a cationic intermediate.
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: Journal of the American Chemical Society
سال: 2014
ISSN: 0002-7863,1520-5126
DOI: 10.1021/ja502792s