Highly Regiocontrolled Pd-Catalyzed Cross-Coupling Reaction of Terminal Alkynes and Allenylphosphine Oxides
作者:Michael Rubin、Jelena Markov、Stepan Chuprakov、Donald J. Wink、Vladimir Gevorgyan
DOI:10.1021/jo034486o
日期:2003.8.1
terminal alkynes 1 with allenylphosphine oxides 2 catalyzed by a Pd(OAc)(2)-TDMPP system provided conjugated endo-enynes 3 solely, while the TCPC-catalyzed reaction of the same regents led to the exclusive formation of exo-isomers 4. The mechanistic rationale for these selective transformations was proposed. Synthetic usefulness of the prepared exo-enyne 4 was demonstrated in the synthesis of multisubstituted
Cycloaddition Reactions of Allenylphosphonates and Related Allenes with Dialkyl Acetylenedicarboxylates, 1,3-Diphenylisobenzofuran, and Anthracene
作者:K. V. Sajna、Ramesh Kotikalapudi、Manab Chakravarty、N. N. Bhuvan Kumar、K. C. Kumara Swamy
DOI:10.1021/jo102240u
日期:2011.2.4
opening of the [β,γ] carbon−carbon double bond of the allene is realized. In contrast to these, the reaction of allenylphosphonate (OCH2CMe2CH2O)P(O)(H)C═C═CMe2 possessing a terminal ═CMe2 group with DMAD occurs by both [2 + 2] cycloaddition and ene reaction. While the reaction of ═CH2 terminal allenylphosphonates as well as allenylphosphine oxides with 1,3-diphenylisobenzofuran afforded preferentially
The rhodium-catalyzed intermolecular asymmetric hydroalkoxylation and hydrosulfenylation of diphenylphosphinylallenes gave chiral allylicphosphine oxides substituted with vinylether and thioether moieties in high yields with high enantioselectivities.
Palladium(II)-Catalyzed Regio- and Stereoselective Hydroarylation of Diphenylphosphorylallenes with Arylboronic Acids in the Presence of Sodium Hydroxide and Oxygen
The palladium(II)‐catalyzed hydroarylation of diphenylphosphorylallenes (via 1,2‐addition of the allenic double bond) with arylboronicacids in the presence of sodium hydroxide and oxygen is developed. The regioselectivities turn out to be well controlled, affording 2‐aryl‐3‐(diphenylphosphinyl)alkenes as the only product. Moreover, the stereoselectivities for reactions of γ‐substituted allenes can
A cooperative CuBr2 and tert‐butyl hydroperoxide (TBHP) system allowed for the highly stereoselective dibromination and bromohydroxylation reactions of (diphenylphosphoryl)allenes under mild conditions.