Cyclopropanation of Allylic Alcohols using Substituted Haloalkylzinc Reagents: Synthesis of gem-Dimethylcyclopropanes
作者:André B. Charette、Nicole Wilb
DOI:10.1055/s-2002-19345
日期:——
gem-Dimethylcyclopropanes were obtained by a cyclopropanation of allylic alcohols and ethers using a mixture of diethylzinc and 2,2-diiodopropane in 53-96% yields. Enantioenriched gem-dimethylcyclopropanes were also synthesized using a glucose-derived auxiliary.
Alkenyl (or aryl) iodide (or bromide) is readily reduced with CrCl2 is N,N-dimethylformamide at 25°C to gice the corresponding organochromium species which adds selectively to an aldehyde moiety without affecting the coexisting ketone or cyano group of the substrate.
Gold(I)-Catalyzed Ring Expansions of Unactivated Alkynylcyclopropanes to (<i>E</i>)-2-Alkylidenecyclobutanamines in the Presence of Sulfonamides
作者:Siyu Ye、Zhi-Xiang Yu
DOI:10.1021/ol9028786
日期:2010.2.19
The ringexpansion of cyclopropane derivatives provides a powerful method to construct synthetically useful four-membered carbocycles. Herein, a new type of gold(I)-catalyzed ringexpansion of an unactivated alkynylcyclopropane/sulfonamide trapping strategy to (E)-2-alkylidenecyclobutanamines was described. The reaction tolerates a range of aryl and alkyl substituents with moderate to good yields.
Cobalt‐Catalyzed Reductive Dimethylcyclopropanation of 1,3‐Dienes
作者:Jacob Werth、Christopher Uyeda
DOI:10.1002/anie.201807542
日期:2018.10.15
variant of the Simmons–Smith reaction that enables the efficient dimethylcyclopropanation of 1,3‐dienes using a Me2CCl2/Zn reagent mixture. The reactions proceed with high regioselectivity based on the substitution pattern of the 1,3‐diene. The products are vinylcyclopropanes, which serve as substrates for transition‐metal‐catalyzed ring‐opening reactions, including 1,3‐rearrangement and [5+2] cycloaddition
[EN] METHODS TO PRODUCE ORGANOTIN COMPOSITIONS WITH CONVENIENT LIGAND PROVIDING REACTANTS<br/>[FR] PROCÉDÉS DE PRODUCTION DE COMPOSITIONS D'ORGANOÉTAIN AU MOYEN DE RÉACTIFS COMMODES FOURNISSANT UN LIGAND
申请人:INPRIA CORP
公开号:WO2022046736A1
公开(公告)日:2022-03-03
Synthesis reactions are described to efficiently and specifically form compounds of the structure RSnL3, where R is an organic ligand to the tin, and L is hydrolysable ligand or a hydrolysis product thereof. The synthesis is effective for a broad range of R ligands. The synthesis is based on the use of alkali metal ions and optionally alkaline earth (pseudo-alkaline earth) metal ions. Compounds are formed of the structures represented by the formulas RSn(C≡CSiR'3)3, R'R"ACSnL3, where A is a halogen atom (F, Cl, Br or I) or an aromatic ring with at least one halogen substituent, R'R"(R'"O)CSnL3 or R'R"(N≡C)CSnZ3.