1,2-Ferrocenediylazaphosphinines: An Unusual Coordination Behavior and Application to Allylic Alkylation
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- 作者：Thanh Thien Co ; Seung Whan Paek ; Sang Chul Shim ; Chan Sik Cho ; Tae-Jeong Kim ; Dong Woong Choi ; Sang Ook Kang ; and Jong Hwa Jeong
- 刊名：Organometallics
- 出版年：2003
- 出版时间：March 31, 2003
- 年：2003
- 卷：22
- 期：7
- 页码：1475 - 1482
- 全文大小：189K
- 年卷期：v.22,no.7(March 31, 2003)
- ISSN：1520-6041
文摘
The reaction of 1,2-ferrocenediylazaphosphinines (1a, R1 = H; 1b, R1 = Me; 1c, R1 = Ph)with M(CO)6 (M = Mo, W), MX(CO)5 (M = Mn, Re; X = Br, Cl), and [Pd(
3-C3H5)Cl]2 showsa strong tendency to adopt an unusual chelating bidentate coordination through nitrogenand the carbonyl oxygen, yielding M(2-N,O)(CO)4 (2, M = Mo; 3, M = W), M(2-N,O)(X)(CO)3 (6, M = Mn, X = Br; 7, M = Re, X = Cl), and [Pd(2-N,O)(3-C3H5)]BF4 (after treatmentwith AgBF4) (8), respectively. X-ray crystallographic structure determinations of 3a (R1 =H) and 8a (R1 = H) show the formation of a five-membered metallacycle with the distanceof the metal-carbonyl oxygen bond being shorter than that of the metal-nitrogen bond inboth compounds. The complexes 2 and 3 further undergo oxidative addition with allyl iodideto yield the corresponding M(II) complexes of the type [M(2-N,O)( 3-C3H5)(I)(CO)2] (4, M =Mo; 5, M = W). Complexes 2-5 and 8 were employed as catalysts for nucleophilic allylicsubstitution of allyl acetates as a probe for both regio- and enantioselectivities of the reaction.All reactions involving unsymmetrical allyl acetates (E)-RCH=CHCH2OAc (R = Pr, Ph) ledexclusively to the formation of achiral linear product (E)-RCH=CHCH2Nu regardless of thetype of catalysts, the ligand, or the allyl substrate employed. One exception to the abovestatement is the observation that Mo- and W-based catalysts (2-5) are totally inactive towardthe allylic substitution of cinnamyl acetate (R = Ph). Asymmetric allylic alkylation of asymmetrically 1,3-disubstituted substrate, PhCH=CHCH(OAc)Ph, is accomplished only byPd-catalysts (8) with enantiomeric excesses up to 50% ee.
3-C3H5)Cl]2 showsa strong tendency to adopt an unusual chelating bidentate coordination through nitrogenand the carbonyl oxygen, yielding M(2-N,O)(CO)4 (2, M = Mo; 3, M = W), M(2-N,O)(X)(CO)3 (6, M = Mn, X = Br; 7, M = Re, X = Cl), and [Pd(2-N,O)(3-C3H5)]BF4 (after treatmentwith AgBF4) (8), respectively. X-ray crystallographic structure determinations of 3a (R1 =H) and 8a (R1 = H) show the formation of a five-membered metallacycle with the distanceof the metal-carbonyl oxygen bond being shorter than that of the metal-nitrogen bond inboth compounds. The complexes 2 and 3 further undergo oxidative addition with allyl iodideto yield the corresponding M(II) complexes of the type [M(2-N,O)( 3-C3H5)(I)(CO)2] (4, M =Mo; 5, M = W). Complexes 2-5 and 8 were employed as catalysts for nucleophilic allylicsubstitution of allyl acetates as a probe for both regio- and enantioselectivities of the reaction.All reactions involving unsymmetrical allyl acetates (E)-RCH=CHCH2OAc (R = Pr, Ph) ledexclusively to the formation of achiral linear product (E)-RCH=CHCH2Nu regardless of thetype of catalysts, the ligand, or the allyl substrate employed. One exception to the abovestatement is the observation that Mo- and W-based catalysts (2-5) are totally inactive towardthe allylic substitution of cinnamyl acetate (R = Ph). Asymmetric allylic alkylation of asymmetrically 1,3-disubstituted substrate, PhCH=CHCH(OAc)Ph, is accomplished only byPd-catalysts (8) with enantiomeric excesses up to 50% ee.