Stereoselective nitrone additions to vinylphosphine derivatives: effect of phosphorus substituents on reaction diastereoselectivity
作者:Alberto Brandi、Stefano Cicchi、Andrea Goti、K. Michal Pietrusiewicz、Maria Zablocka、Witold Wisniewski
DOI:10.1021/jo00014a011
日期:1991.7
Meaningful diastereofacial selectivity in cycloaddition of 2,2-dimethyl-3,4-pyrroline N-oxide (DMPO) to 12 structurally diversified vinylphosphine derivatives 1-12 has been achieved by proper choice of the polar substituent on phosphorus combined with effective steric differentiation of the remaining substituents. The unique sense of induction in all these reactions is consistent with the assumption that vinylphosphorus dipolarophiles prefer an s-cisoid array of C = C - P = X fragments in their reactive conformations. Use of divinylphosphine derivatives in such reactions exemplifies the possibility of synthesizing chiral phosphine oxides and sulfides from prochiral precursors in a highly selective and stereochemically predictable manner. An observation that in P-31 NMR spectra the adducts of type I are uniformly found at lower field than adducts of type II facilitates the stereochemical assignments.
BRANDI, ALBERTO;CICCHI, STEFANO;GOTI, ANDREA;PIETRUSIEWICZ, K. MICHAL;ZAB+, J. ORG. CHEM., 56,(1991) N4, C. 4383-4388
作者:BRANDI, ALBERTO、CICCHI, STEFANO、GOTI, ANDREA、PIETRUSIEWICZ, K. MICHAL、ZAB+
DOI:——
日期:——
Rhodium-Catalyzed Enantioposition-Selective Hydroarylation of Divinylphosphine Oxides with Aryl Boroxines
作者:Zhe Wang、Tamio Hayashi
DOI:10.1002/anie.201712572
日期:2018.2.5
undergoes oxidative arylation while the other one is reduced to an ethyl moiety. These reactions proceed with high selectivity in terms of the enantiotopic vinyl groups in the presence of (R)‐DTBM‐segphos/Rh to give the P‐stereogenic monoarylation products with high enantioselectivity.