Hydrozirconation of acetylenic chalcogenides. Synthesis and reactions of zirconated vinyl chalcogenide intermediates
摘要:
Acetylenic tellurides react with Cp2Zr(H)Cl in THF at room temperature to give the alpha-zirconated vinyl telluride intermediates 39, which react with a wide range of electrophiles to give several types of trisubstituted olefins, such as alpha-halo vinyl tellurides, ketene telluro(seleno) acetals, ketene telluro acetals, and vinylic tellurides of Z configuration. Acetylenic selenides undergo similar reactions, but a lack of regioselectivity results in the formation of a mixture of alpha-zirconated 19 and beta- zirconated 20 vinylic selenide intermediates. After a derailed study was established that the use of 2.0 equivalents of Cp2Zr(H)Cl is crucial to perform the total hydrozirconation of acetylenic selenides or tellurides. (C) 1998 Elsevier Science Ltd. All rights reserved.
Regio-and Stereoselective Synthesis of (E)-1-Alkylseleno-1, 4-Pentadienes by Cross-Coupling of Allyl Bromide with Alkyl-selenovinylcoppers from Alkylselenovinyldialkylboranes
作者:De-Yu Yang、Xian Huang
DOI:10.1080/00397919608003839
日期:1996.12
cuprous bromide-methyl sulfide to generate alkylselenovinylcopper intermediates which underwent stereospecific cross-coupling with allylbromide to yield (E)-1-alkylseleno-1, 4-pentadienes 3. The compounds 3 were formed with retention of configuration predetermined from the stereochemistry of the initial alkylselenovinylboranes.
A Stereoselective Route to (E)-Vinylic Selenides through the Palladium-Catalyzed Cross-Coupling Reaction of Selenovinylicdialkylboranes with Alkyl Halides
作者:Yu Yang、Xian Huang
DOI:10.1080/00397919708005038
日期:1997.1
Abstract The reaction of selenoviylicdialkyboranes with alkyl halides takes place readily in the presence of Pd(PPh3)4 and sodium methoxide to afford (E)-vinylic selenides in excellent yields
Regio- and Stereoselective Conversion of Terminal Alkylselenoacetylenes into (E)-2-Alkylseleno-1-Vinylic Iodides via Hydroboration-Iodination
作者:De-Yu Yang、Xian Huang
DOI:10.1080/00397919608004786
日期:1996.12
The hydroboration of terminal alkylselenoacetylenes 1 in the presence of 3 mol% of Pd (PPh(3))(4) with catecholborane 2 followed by hydrolysis, undergo a rapid reaction with iodine under the influence of sodium hydroxide at-10 degrees C in THF to afford a novel method for the regio-and stereospecific synthesis of (E)-2-alkylseleno-1-vinyl iodides 4.
AMOSOVA, S. V.;POTAPOV, V. A.;KEJKO, V. V.;ROMANENKO, L. S.;VITKOVSKIJ, V+, METALLOORGAN. XIMIYA, 4,(1991) N, S. 950-951
作者:AMOSOVA, S. V.、POTAPOV, V. A.、KEJKO, V. V.、ROMANENKO, L. S.、VITKOVSKIJ, V+
DOI:——
日期:——
Hydrozirconation of acetylenic chalcogenides. Synthesis and reactions of zirconated vinyl chalcogenide intermediates
作者:Miguel J. Dabdoub、Mauro L. Begnini、Palimécio G. Guerrero
DOI:10.1016/s0040-4020(98)00014-3
日期:1998.3
Acetylenic tellurides react with Cp2Zr(H)Cl in THF at room temperature to give the alpha-zirconated vinyl telluride intermediates 39, which react with a wide range of electrophiles to give several types of trisubstituted olefins, such as alpha-halo vinyl tellurides, ketene telluro(seleno) acetals, ketene telluro acetals, and vinylic tellurides of Z configuration. Acetylenic selenides undergo similar reactions, but a lack of regioselectivity results in the formation of a mixture of alpha-zirconated 19 and beta- zirconated 20 vinylic selenide intermediates. After a derailed study was established that the use of 2.0 equivalents of Cp2Zr(H)Cl is crucial to perform the total hydrozirconation of acetylenic selenides or tellurides. (C) 1998 Elsevier Science Ltd. All rights reserved.