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Coordination and Coupling of OH-Functionalized C 2 Units at a Single Metal Center: The Synthesis of Alkynyl(Vinylidene), Alkynyl(Enyne), Bis(Alkynyl)Hydrido, Enynyl, and Hexapentaene Rhodium Complexes from Propargylic Alcohols as Precursors.

Authors :
Werner H
Wiedemann R
Mahr N
Steinert P
Wolf J
Source :
Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 1996 May; Vol. 2 (5), pp. 561-569.
Publication Year :
1996

Abstract

The reaction of [Rh(η <superscript>3</superscript> -C <subscript>3</subscript> H <subscript>5</subscript> )-(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (1) with HCCCH(Ph)OH yields the alkynyl(vinylidene) complex trans-[Rh{CCCH(Ph)OH}{CCH-CH(Ph)OH}(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (2), while from 1 and HCCCPh <subscript>2</subscript> OH the alkynyl-(enyne)metal derivative trans-[Rh(CCCPh <subscript>2</subscript> OH){n <superscript>2</superscript> -(E)-Ph <subscript>2</subscript> (OH)CCCCHCH-CPh <subscript>2</subscript> OH} (PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (3) is obtained. On treatment with 1-alkyn-3-ols HCCCR <subscript>2</subscript> OH (R = Me, Ph, iPr), the highly reactive π-benzyl compound [Rh(n <superscript>3</superscript> -CH <subscript>2</subscript> Ph)(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (4) yields the five-coordinate complexes [RhH(CCCR <subscript>2</subscript> OH) <subscript>2</subscript> (PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (5-7) of which those with R = Me and Ph can be converted to the alkynyl(vinylidene)metal isomers trans-[Rh(CCCR <subscript>2</subscript> OH)(CCH-CR <subscript>2</subscript> OH)-(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (8, 9). Compounds 8 and 9 react with L' = CO and isocyanides by migration of the alkynyl ligand to the vinylidene unit to give the enynylrhodium(I) complexes trans-[Rh{n <superscript>1</superscript> -(Z)-C(CCCR <subscript>2</subscript> OH)CH-CR <subscript>2</subscript> OH}(L')(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (10, 11: L' = CO; 12-15: L' = CNR'). Cleavage of the Rh-C s̀-bond of 10 with CF <subscript>3</subscript> -CO <subscript>2</subscript> H affords trans-[Rh(n <superscript>1</superscript> -O <subscript>2</subscript> CCF <subscript>3</subscript> )-(CO)(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (16) and the enyne (E)-Me <subscript>2</subscript> (OH)CCCCHCH-CMe <subscript>2</subscript> OH (17). Compounds 5-7 react with L' = CO and isocyanides to give the octahedral 1:1 adducts [RhH(CCCR <subscript>2</subscript> OH) <subscript>2</subscript> (L')(P-iPr <subscript>3</subscript> ) <subscript>2</subscript> ] (18-20 and 24-27), of which the CO derivatives 18-20 readily eliminate HCCCR <subscript>2</subscript> OH to yield trans-[Rh-(CCCR <subscript>2</subscript> OH)(CO)(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (21-23). On treatment of 6 or 9 (R = Ph) with Al <subscript>2</subscript> O <subscript>3</subscript> in the presence of chloride ions, besides trans-[RhCl(CCCPh <subscript>2</subscript> )(P-iPr <subscript>3</subscript> ) <subscript>2</subscript> ] (28) the hexapentaenerhodium(I) complex trans-[RhCl(n <superscript>2</superscript> -Ph <subscript>2</subscript> CCCCCCPh <subscript>2</subscript> )(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] (29) is formed. The kinetically preferred isomer trans-[RhCl(n <superscript>2</superscript> -Ph <subscript>2</subscript> CCCCCCPh <subscript>2</subscript> )(P-iPr <subscript>3</subscript> ) <subscript>2</subscript> ] (33) has been prepared from [RhCl(PiPr <subscript>3</subscript> ) <subscript>2</subscript> ] <subscript>2</subscript> and Ph <subscript>2</subscript> CCCCCCPh <subscript>2</subscript> ; it rearranges smoothly at room temperature to the thermodynamically more stable isomer 29. The molecular structures of 7 and 29 have been determined.<br /> (Copyright © 1996 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Details

Language :
English
ISSN :
1521-3765
Volume :
2
Issue :
5
Database :
MEDLINE
Journal :
Chemistry (Weinheim an der Bergstrasse, Germany)
Publication Type :
Academic Journal
Accession number :
29178219
Full Text :
https://doi.org/10.1002/chem.19960020516
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