25755-73-1Relevant articles and documents
Synthesis of Allylboranes via Cu(I)-Catalyzed B-H Insertion of Vinyldiazoacetates into Phosphine-Borane Adducts
Drikermann, Denis,M??el, Robert S.,Al-Jammal, Walid K.,Vilotijevic, Ivan
supporting information, p. 1091 - 1095 (2020/02/15)
Cu(I) catalysts enable C-B bond formation via direct insertion of vinyldiazoacetates into B-H bonds of borane-phosphine Lewis adducts to form phosphine-protected allylboranes under mild conditions. The resulting allylborane-phosphine Lewis adducts can be used in the diastereoselective allylation of aldehydes directly without the need for removal of the phosphine. The allylation reaction proceeds with high diastereoselectivity and yields 5,6-disubstituted dihydropyranones after treatment with an appropriate acid.
Regiodivergent Hydroborative Ring Opening of Epoxides via Selective C-O Bond Activation
Magre, Marc,Paffenholz, Eva,Maity, Bholanath,Cavallo, Luigi,Rueping, Magnus
supporting information, p. 14286 - 14294 (2020/09/15)
A magnesium-catalyzed regiodivergent C-O bond cleavage protocol is presented. Readily available magnesium catalysts achieve the selective hydroboration of a wide range of epoxides and oxetanes yielding secondary and tertiary alcohols in excellent yields and regioselectivities. Experimental mechanistic investigations and DFT calculations provide insight into the unexpected regiodivergence and explain the different mechanisms of the C-O bond activation and product formation.
Nickel-catalyzed regiodivergent opening of epoxides with aryl halides: Co-catalysis controls regioselectivity
Zhao, Yang,Weix, Daniel J.
supporting information, p. 48 - 51 (2014/01/23)
Epoxides are versatile intermediates in organic synthesis, but have rarely been employed in cross-coupling reactions. We report that bipyridine-ligated nickel can mediate the addition of functionalized aryl halides, a vinyl halide, and a vinyl triflate to epoxides under reducing conditions. For terminal epoxides, the regioselectivity of the reaction depends upon the cocatalyst employed. Iodide cocatalysis results in opening at the less hindered position via an iodohydrin intermediate. Titanocene cocatalysis results in opening at the more hindered position, presumably via TiIII-mediated radical generation. 1,2-Disubstituted epoxides are opened under both conditions to form predominantly the trans product.
Synthesis of optically active β- Or γ-alkyl-substituted alcohols through copper-catalyzed asymmetric allylic alkylation with organolithium reagents
Guduguntla, Sureshbabu,Fananas-Mastral, Martin,Feringa, Ben L.
, p. 8274 - 8280 (2013/09/24)
An efficient one-pot synthesis of optically active β-alkyl-substituted alcohols through a tandem copper-catalyzed asymmetric allylic alkylation (AAA) with organolithium reagents and reductive ozonolysis is presented. Furthermore, hydroboration-oxidation following the Cu-catalyzed AAA leads to the corresponding homochiral γ-alkyl-substituted alcohols.
Gold-Catalyzed Electrophilic Addition to Arylalkynes. A Facile Method for the Regioselective Synthesis of Substituted Naphthalenes
Balamurugan, Rengarajan,Gudla, Vanajakshi
supporting information; experimental part, p. 3116 - 3119 (2009/12/05)
An interesting gold-catalyzed electrophilic addition to arylalkyne to synthesize substituted naphthalenes has been presented. Different metal hexafluoroantimonates have also been found to effect the transformation. Counter anion and oxo- and alkynophilicities of catalytic gold species might play an important role in this annulation reaction.
ORGANOCOPPER REAGENTS IN DIMETHYL SULFIDE
Bertz, Steven H.,Dabbagh, Gary
, p. 425 - 434 (2007/10/02)
Organocopper(I) reagents, RCu, are both more stable and more reactive when prepared in dimethyl sulfide instead of ether or tetrahydrofuran.A wide range of Li reagents has been investigated with good results, as has a selection of Grignard reagents.Excellent yields of products are observed with typical substrates as α,β-unsaturated ketones and acid chlorides.
Substitution Reactions of Secondary Halides and Epoxides with Higher Order, Mixed Organocuprates, R2Cu(CN)Li2: Synthetic, Stereochemical, and Mechanistic Aspects
Lipshutz, Bruce H.,Wilhelm, Robert S.,Kozlowski, Joseph A.,Parker, David
, p. 3928 - 3938 (2007/10/02)
Higher order cuprates, represented by the general formula R2Cu(CN)Li2, are readily prepared from copper cyanide and 2 equiv of an organolithium.These novel reagents react readily and efficiently with secondary unactivated iodides and bromides affording products of substitution.Likewise, mono-, di-, and trisubstituted epoxides undergo ring opening leading to the corresponding alcohols in excellent yields.The effects of solvent, temperature, gegenion, and variations in ligands are discussed.Replacement of the second equivalent of RLi by CH3Li strongly encouragestransfer of R over CH3 in R(CH3)Cu(CN)Li2 with halides.Use of PhLi as RRLi in place of one RTLi (i.e.RT(Ph)Cu(CN)Li2) is suggested for oxirane cleavage.The stereochemical implications associated with both couplings are also addressed.
