347360-16-1Relevant articles and documents
Halide ion effects in the rhodium-catalyzed allylic substitution reaction using copper(I) alkoxides and enolates
Evans, P. Andrew,Leahy, David K.,Slieker, Laura M.
, p. 3613 - 3618 (2003)
The transmetallation of lithium alkoxides and enolates with a copper(I) halide salt provides the requisite nucleophiles to accomplish the stereospecific rhodium-catalyzed allylic substitution. These studies demonstrate that the nature of the halide ion derived from the copper(I) salt has a profound effect on regioselectivity and enantiospecificity. This observation was attributed to the trans-effect, by virtue of an in situ modification of the catalyst by the halide ion, which leads to modulated catalytic activity and improved stereospecificity.
The influence of α-coordinating groups of aldehydes on E/Z-selectivity and the use of quaternary ammonium counter ions for enhanced E-selectivity in the Julia–Kocienski reaction
Rehman, Mintu,Surendran, Sravya,Siddavatam, Nagendra,Rajendar, Goreti
supporting information, p. 329 - 333 (2022/01/20)
Modified reaction conditions for improved E-selectivity of olefins in the Julia–Kocienski reaction of aldehydes having α-coordinating substituents are demonstrated. The chelating groups in aldehydes are expected to stabilize the syn-transition state with metal ions, whereas the weakly coordinating quaternary ammonium ions are devoid of all possible chelating interactions to enhance E-selectivity. A systematic investigation is presented to study the size of the neighbouring protecting groups of aldehydes and their chelation effect on E/Z-selectivity in the Julia–Kocienski reaction.
Nickel(0) triethyl phosphite complex-catalyzed allylic substitution with retention of regio- and stereochemistry
Yatsumonji, Yasutaka,Ishida, Yusuke,Tsubouchi, Akira,Takeda, Takeshi
, p. 4603 - 4606 (2008/03/12)
(Chemical Equation Presented) Nickel(0) triethyl phosphite complex-promoted reaction of allylic acetates with thiols produced allylic sulfides with retention of configuration without allylic rearrangement. A similar reaction of allylic acetates with alcohols and phenols also proceeded with retention of regio- and stereochemistry.
Facially controlled C-methylation of oxolanyl and cyclopentyl acetate enolates: Application to the total synthesis of (+)-nephromopsinic acid
Mulzer, Johann,Steffen, Ulrich,Martin, Harry J.,Zorn, Ludwig
, p. 1028 - 1043 (2007/10/03)
The stereoselectivity of the C-methylation of oxolanyl and cyclopentyl acetate enolates 5a-22a was investigated. The configuration of the C-methyl diastereomers was elucidated by a combination of crystal structure analysis, NMR spectroscopy and chemical correlations. Generally, the methylation proceeded re*-selectively, although with very different degrees of selectivity. The most important stereodirecting effect was a steric one exerted by the 5-phenethyl substituent, and this steric effect was strongly increased by the stereodirecting effect of a 3-OR group. Contrary to previous literature evidence, the endocyclic oxolanyl oxygen does not exert an effect. These findings were applied in a highly stereoselective synthesis of (+)-nephromopsinic acid (94). Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
Regio- and enantiospecific rhodium-catalyzed allylic etherification reactions using copper(I) alkoxides: Influence of the copper halide salt on selectivity
Evans, P. Andrew,Leahy, David K.
, p. 7882 - 7883 (2007/10/03)
The transition metal-catalyzed allylic etherification represents a fundamentally important cross-coupling reaction for the construction of allylic ethers. We have developed a new regio- and enantiospecific rhodium-catalyzed allylic etherification of acycl
