Organolathanide-Catalyzed Regioselective Intermolecular Hydroamination of Alkenes, Alkynes, Vinylarenes, Di- and Trivinylarenes, and Methylenecyclopropanes. Scope and Mechanistic Comparison to Intramo
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- 作者：Jae-Sang Ryu ; George Yanwu Li ; and Tobin J. Marks
- 刊名：Journal of the American Chemical Society
- 出版年：2003
- 出版时间：October 15, 2003
- 年：2003
- 卷：125
- 期：41
- 页码：12584 - 12605
- 全文大小：480K
- 年卷期：v.125,no.41(October 15, 2003)
- ISSN：1520-5126
文摘
Organolanthanide complexes of the type Cp'2LnCH(SiMe3)2 (Cp' = 
5-Me5C5; Ln = La, Nd, Sm,Lu) and Me2SiCp' '2LnCH(SiMe3)2 (Cp' ' = 5-Me4C5; Ln = Nd, Sm, Lu) serve as efficient precatalysts forthe regioselective intermolecular hydroamination of alkynes R'C
CMe (R' = SiMe3, C6H5, Me), alkenesRCH=CH2 (R = SiMe3, CH3CH2CH2), butadiene, vinylarenes ArCH=CH2 (Ar = phenyl, 4-methylbenzene,naphthyl, 4-fluorobenzene, 4-(trifluoromethyl)benzene, 4-methoxybenzene, 4-(dimethylamino)benzene,4-(methylthio)benzene), di- and trivinylarenes, and methylenecyclopropanes with primary amines R' 'NH2(R' ' = n-propyl, n-butyl, isobutyl, phenyl, 4-methylphenyl, 4-(dimethylamino)phenyl) to yield the correspondingamines and imines. For R = SiMe3, R = CH2=CH lanthanide-mediated intermolecular hydroaminationregioselectively generates the anti-Markovnikov addition products (Me3SiCH2CH2NHR' ', (E)-CH3CH=CHCH2NHR' '). However, for R = CH3CH2CH2, the Markovnikov addition product is observed (CH3CH2CH2CHNHR' 'CH3). For internal alkynes, it appears that these regioselective transformations occur undersignificant stereoelectronic control, and for R' = SiMe3, rearrangement of the product enamines occurs viatautomerization to imines, followed by a 1,3-trimethylsilyl group shift to stable N-SiMe3-bonded CH2=CMeN(SiMe3)R' ' structures. For vinylarenes, intermolecular hydroamination with n-propylamine affords the anti-Markovnikov addition product 
-phenylethylamine. In addition, hydroamination of divinylarenes provides aconcise synthesis of tetrahydroisoquinoline structures via coupled intermolecular hydroamination/subsequentintramolecular cyclohydroamination sequences. Intermolecular hydroamination of methylenecyclopropaneproceeds via highly regioselective exo-methylene C=C insertion into Ln-N bonds, followed by regioselectivecyclopropane ring opening to afford the corresponding imine. For the Me2SiCp' '2Nd-catalyzed reaction ofMe3SiCCMe and H2NCH2CH2CH2CH3, 
H
= 17.2 (1.1) kcal mol-1 and S = -25.9 (9.7) eu, while thereaction kinetics are zero-order in [amine] and first-order in both [catalyst] and [alkyne]. For the samesubstrate pair, catalytic turnover frequencies under identical conditions decrease in the order Me2SiCp' '2NdCH(SiMe3)2 > Me2SiCp' '2SmCH(SiMe3)2 > Me2SiCp' '2LuCH(SiMe3)2 > Cp'2SmCH(SiMe3)2, in accordwith documented steric requirements for the insertion of olefinic functionalities into lanthanide-alkyl and-heteroatom 
-bonds. Kinetic and mechanistic evidence argues that the turnover-limiting step isintermolecular C=C/CC bond insertion into the Ln-N bond followed by rapid protonolysis of the resultingLn-C bond.
5-Me5C5; Ln = La, Nd, Sm,Lu) and Me2SiCp' '2LnCH(SiMe3)2 (Cp' ' = 5-Me4C5; Ln = Nd, Sm, Lu) serve as efficient precatalysts forthe regioselective intermolecular hydroamination of alkynes R'CCMe (R' = SiMe3, C6H5, Me), alkenesRCH=CH2 (R = SiMe3, CH3CH2CH2), butadiene, vinylarenes ArCH=CH2 (Ar = phenyl, 4-methylbenzene,naphthyl, 4-fluorobenzene, 4-(trifluoromethyl)benzene, 4-methoxybenzene, 4-(dimethylamino)benzene,4-(methylthio)benzene), di- and trivinylarenes, and methylenecyclopropanes with primary amines R' 'NH2(R' ' = n-propyl, n-butyl, isobutyl, phenyl, 4-methylphenyl, 4-(dimethylamino)phenyl) to yield the correspondingamines and imines. For R = SiMe3, R = CH2=CH lanthanide-mediated intermolecular hydroaminationregioselectively generates the anti-Markovnikov addition products (Me3SiCH2CH2NHR' ', (E)-CH3CH=CHCH2NHR' '). However, for R = CH3CH2CH2, the Markovnikov addition product is observed (CH3CH2CH2CHNHR' 'CH3). For internal alkynes, it appears that these regioselective transformations occur undersignificant stereoelectronic control, and for R' = SiMe3, rearrangement of the product enamines occurs viatautomerization to imines, followed by a 1,3-trimethylsilyl group shift to stable N-SiMe3-bonded CH2=CMeN(SiMe3)R' ' structures. For vinylarenes, intermolecular hydroamination with n-propylamine affords the anti-Markovnikov addition product -phenylethylamine. In addition, hydroamination of divinylarenes provides aconcise synthesis of tetrahydroisoquinoline structures via coupled intermolecular hydroamination/subsequentintramolecular cyclohydroamination sequences. Intermolecular hydroamination of methylenecyclopropaneproceeds via highly regioselective exo-methylene C=C insertion into Ln-N bonds, followed by regioselectivecyclopropane ring opening to afford the corresponding imine. For the Me2SiCp' '2Nd-catalyzed reaction ofMe3SiCCMe and H2NCH2CH2CH2CH3, H = 17.2 (1.1) kcal mol-1 and S = -25.9 (9.7) eu, while thereaction kinetics are zero-order in [amine] and first-order in both [catalyst] and [alkyne]. For the samesubstrate pair, catalytic turnover frequencies under identical conditions decrease in the order Me2SiCp' '2NdCH(SiMe3)2 > Me2SiCp' '2SmCH(SiMe3)2 > Me2SiCp' '2LuCH(SiMe3)2 > Cp'2SmCH(SiMe3)2, in accordwith documented steric requirements for the insertion of olefinic functionalities into lanthanide-alkyl and-heteroatom -bonds. Kinetic and mechanistic evidence argues that the turnover-limiting step isintermolecular C=C/CC bond insertion into the Ln-N bond followed by rapid protonolysis of the resultingLn-C bond.