129518-69-0Relevant articles and documents
Diastereoselective Synthesis of Cyclopropyl Boronic Esters
Pietruszka, J?rg,Widenmeyer, Markus
, p. 977 - 979 (1997)
The conversion of simple 1-alkynes to optically active 2-alkyl-cyclopropan-1-ols is conveniently achieved by a simple protocol. The key step is the cyclopropanation of alkenyl boronic esters derived from (4-)-diisopropyl L-tartrate and alkenyl boronic acids. It has been found that best yields could be obtained using diazomethane and palladium(II) acetate as catalyst. The systematic investigation of parameters influencing this reaction led to an improvement of the diastereoselectivity of the transformation.
Exploiting the enantioselectivity of Baeyer-Villiger monooxygenases via boron oxidation
Brondani, Patricia B.,Dudek, Hanna,Reis, Joel S.,Fraaije, Marco W.,Andrade, Leandro H.
experimental part, p. 703 - 708 (2012/09/21)
The enantioselective carbon-boron bond oxidation of several chiral boron-containing compounds by Baeyer-Villiger monooxygenases was evaluated. PAMO and M446G PAMO conveniently oxidized 1-phenylethyl boronate into the corresponding 1-(phenyl)ethanol (ee = 82-91%). Cyclopropyl boronic esters were also oxidized but with no enantioselectivity. β-Boryl carboxylic esters were not oxidized by any BVMOs.
Enantioselective synthesis of trans-aryl-and-heteroaryl-substituted cyclopropylboronates by copper (I)-catalyzed reactions of allylic phosphates with a diboron derivative
Zhong, Chongmin,Kunii, Shun,Kosaka, Yuki,Sawamura, Masaya,Ito, Hajime
supporting information; experimental part, p. 11440 - 11442 (2010/10/04)
A new asymmetric route for the synthesis of trans-2-aryl- and -heteroaryl-substituted cyclopropylboronates has been developed. (Z)-3-arylallylic phosphates were converted to the optically active products with high yield and diastereo- and enantioselectivity through a copper(I)-catalyzed reaction with a diboron derivative. Under mild reaction conditions, the reaction affords the arylcyclopropane products with a functional group and a heteroaromatic group in a highly enantioselective manner. When (E)-allylic phosphates were used as substrates, a ligand-controlled product switch between the trans and cis configurations was observed.
Kinetic Enzymatic Resolution of Cyclopropane Derivatives
Pietruszka, Joerg,Rieche, Anja C. M.,Wilhelm, Thorsten,Witt, Andreas
, p. 1273 - 1286 (2007/10/03)
The kinetic enzymatic resolution of various cyclopropane derivatives was systematically investigated. The study focused on synthetically useful cyclopropylmethanols (e.g., 18a/j or 19a/j) as well as some rarely investigated cyclopropanols (e.g., 24/25 or 27). The combination of enantioselective catalytic or diastereoselective synthesis of enantiomerically enriched compounds with enzymatic approaches ultimately led to the most convenient route to enantiomerically pure starting materials. Again, this was especially proven for the synthesis of cyclopropanols 18a/j and 19a/j. Key to the successful investigation was to rigorously establish an analytical tool for the analysis of enantiomeric composition of reaction mixtures.
Chirality transfer from silicon to carbon via diastereoselective Simmons-Smith cyclopropanation of chiral alkenylsilanols
Yamamura, Yuichi,Toriyama, Fumihiko,Kondo, Tatsuhiro,Mori, Atsunori
, p. 13 - 15 (2007/10/03)
Simmons-Smith cyclopropanation of a chiral alkenylsilanol with CH2I2-Et2Zn proceeds diastereoselectively to give the corresponding cyclopropylsilanol product. Chirality transfer from silicon to the alkenyl carbons of the silicon substituent is observed. The stereochemistry of the obtained cyclopropylsilanol is confirmed by converting to cyclopropanol via Tamao oxidation.
Synthesis of cyclopropylsilanols by the Simmons-Smith reaction of alkenylsilanols and lithium alkenylsilanolates
Hirabayashi, Kazunori,Mori, Atsunori,Hiyama, Tamejiro
, p. 461 - 464 (2007/10/03)
Alkenylsilanols and the corresponding lithium silanolates prepared in situ by the reaction of cyclic siloxanes with alkenyllithiums are transformed to the corresponding cyclopropylsilanols under the Simmons-Smith reaction conditions. The obtained cyclopropylsilanols are further converted into the corresponding cyclopropanols by the Tamao oxidation.
Asymmetric Cyclopropanation of 1-Alkenylboronic Esters and Its Application to the Synthesis of Optically Active Cyclopropanols
Imai, Toshiro,Mineta, Hiroshi,Nishida, Shinya
, p. 4986 - 4988 (2007/10/02)
The first asymmetric cyclopropanation of 1-alkenylboronic esters was realized by diastereofacial selective Simmons-Smith reaction of the esters modified by enantiomerically pure diols such as tetramethyltartaramide.Subsequent oxidation of the resulting cyclopropylboronates gave optically active 2-substituted cyclopropanols in 73-94percent ee.These reactive compounds possess high synthetic potential.
