Advances in the synthesis and reactivity of group 6 metal allenyls

Selected reviews on metal allenyl complexes: (a) Wojcicki A. Allenyls and propargyls: versatile ligands in transition-metal chemistry. Inorg Chem Commun. 2002;5:82–97. Doherty, 1995, Homometallic and heterometallic transition metal allenyl complexes: synthesis, structure, and reactivity, Adv Organomet Chem, 37, 39, 10.1016/S0065-3055(08)60598-5 Wojcicki, 1993, Heterobinuclear and heterotrinuclear transition-metal μ-allenyl complexes, J Clust Sci, 4, 59, 10.1007/BF01028385 For examples of stable group 4 metal allenyl complexes, see: (a) Zhang S, Zhang W-X, Zhao J, Xi Z. Cleavage and reorganization of Zr–C/Si–C bonds leading to Zr/Si–N organometallic and heterocyclic compounds. J Am Chem Soc. 2010;132:14042–14045. Pellny, 2000, Different C–C coupling reactions of permethyltitanocene and Permethylzirconocene with disubstituted 1,3-butadiynes, Chem Eur J, 6, 81, 10.1002/(SICI)1521-3765(20000103)6:1<81::AID-CHEM81>3.0.CO;2-9 Podiyanachan, 2013, Remarkable behavior of a bifunctional alkynylborane zirconocene complex toward donor ligands and acetylenes, J Am Chem Soc, 135, 17444, 10.1021/ja408385h Bender, 2014, Reaction of five-membered zirconacycloallenoids with the strong Lewis acid B(C6F5)3, Dalton Trans, 43, 12210, 10.1039/C4DT01137F Semproni, 2014, N–H and N–C bond formation with an N2-derived dihafnium μ-nitrido complex, Organometallics, 33, 3727, 10.1021/om500393n Podiyanachan, 2014, Catalytic formation of five-membered zirconacycloallenoids and their reaction with carbon dioxide, Organometallics, 33, 3481, 10.1021/om500399w Fan, 2013, Unusual regioselectivity in the aldehyde addition reactions of allenyl/propargyl zirconium complexes derived from γ-(2-pyridyl)propargyl ethers: synthesis of multisubstituted α-Hydroxyallenes, Organometallics, 32, 1636, 10.1021/om301007z Trose, 2018, Dehydropolymerisation of methylamine borane using a dinuclear 1,3-allenediyl bridged zirconocene complex, Dalton Trans, 47, 12858, 10.1039/C8DT03311K Blosser, 1993, η3-bonding of phenylallenyl in a zirconocene complex, J Am Chem Soc, 115, 2994, 10.1021/ja00060a065 Ugolotti, 2008, Five-membered metallacyclic allenoids: synthesis and structure of remarkably stable strongly distorted cyclic allene derivatives, Angew Chem Int Ed, 47, 2622, 10.1002/anie.200705615 Suzuki, 2013, Synthesis of seven-membered cyclic allenes, 1-zirconacyclohepta-2,3,6-trienes, from alkynes and 1-En-3-ynes, J Organomet Chem, 741, 91, 10.1016/j.jorganchem.2013.05.023 Suzuki, 2015, Sulfur-containing stable five-membered “cycloallene” complexes: 1-thia-2-zircona- and 1-thia-2-titanacyclopenta-3,4-dienes, Org Chem Front, 2015, 681, 10.1039/C5QO00072F Suzuki, 2008, Transformation of a 1-zirconacyclopent-3-yne, a five-membered cycloalkyne, into a 1-zirconacyclopent-3-ene and formal “1-zirconacyclopenta-2,3-dienes”, Angew Chem Int Ed, 47, 5198, 10.1002/anie.200800739 Ugolotti, 2009, Five-membered zirconacycloallenoids: synthesis and characterization of members of a unique class of internally metal-stabilized bent allenoid compounds, J Am Chem Soc, 131, 1996, 10.1021/ja8084302 Rei, 2018, Visiting the limits between a highly strained 1-zirconacyclobuta-2,3-diene and chemically robust dizirconacyclooctatetraene, Chem Eur J, 24, 5667, 10.1002/chem.201800465 Breweries, 2007, Reactions of decamethylhafnocene with 1,3-butadiynes: formation of hafnacyclocumulenes and C–H activation at pentamethylcyclopentadienyl ligands, Organometallics, 26, 6827, 10.1021/om700911a Lindenau, 2021, Mechanistic insights into dehydrocoupling of amine boranes using dinuclear zirconocene complexes, Cat Sci Tech, 11, 4034, 10.1039/D1CY00531F For examples of stable group 6 metal allenyl complexes (excluding those derived from Fischer alkoxycarbene complexes), see: (a) Ipakschi J, Reimann K, Serafin M, Dulmer A. η1-Alkynyl and vinylidene transition metal complexes: reaction of the metal-acetylide [(η5-C5H5)(CO)(NO)W-C≡C-(CH3)3]Li with 1,2-diiodoethane as electrophile and with various nucleophiles. J Organomet Chem 2003;670:66–74. Schaffer, 2011, Alkane binding implicated in reactions of (tBu3SiN)3WHK and alkyl halides, Organometallics, 30, 6518, 10.1021/om2009342 Reichmann, 2011, Amino-substituted butatrienes: unusual η1 ligands formed by an unusual reaction, Organometallics, 30, 1215, 10.1021/om101163j Berke, 1981, Dialkylallenylidenekomplexe mit Pentacarbonylfragmenten der VIb-Metalle, Z Naturforsch B: Chem Sci, 36, 929, 10.1515/znb-1981-0807 For examples of stable group 7 metal allenyl complexes, see: (a) Kolobova N, Ivanov LL, Khvanko OS, Khitrova OM, Batsanov AS, Struchkov YT. Cyclopentadienyldicarbonylmanganese phosphonium ylide complexes. X-ray crystal and molecular structure of (η-C5H5)(CO)2MnC(PPh3)=C=CPh2·CH2Cl2. J Organomet Chem 1984;265:271–281. Ortin, 2005, Subtle reactivity patterns of non-heteroatom-substituted manganese alkynyl carbene complexes in the presence of phosphorus probes, Dalton Trans, 2005, 1620, 10.1039/b501008j For examples of stable group 8 metal allenyl complexes, see: (a) Nishimura Y, Arikawa Y, Inoue T, Onishi M. Regioselective nucleophilic addition of triphenylphosphine to the nitrosylruthenium alkynyl complexes having a hydrotris(pyrazol-1-yl)borate: formation of phosphonio-alkenyl, alkynyl, and allenyl species. Dalton Trans. 2005; 930–937. García de la Arada, 2015, Nucleophilic additions to allenylidene ruthenium complexes, Organometallics, 34, 1345, 10.1021/acs.organomet.5b00060 Esteruelas, 1998, Regioselective addition of PRPh2 to the Cα atom of the diphenylallenylidene ligand of [Ru(η5-C5H5)(CCCPh2)(CO)(PPri3)]BF4, Organometallics, 17, 5434, 10.1021/om980577d Arikawa, 2008, Triphenylphosphine incorporation reactions of diynyl complexes containing a TpRu(NO) fragment and isomerization to ruthenacyclobuta[b]naphthalene, Organometallics, 27, 1227, 10.1021/om701028r Buriez, 1999, Unprecedented coupling of vinylidene and allenylidene ligands with dithiocarbamates: X-ray structure of [Ru{C(=C=CPh2)SC(NMe2)S}(S2CNMe2)(CO)(PPh3)], J Organomet Chem, 578, 264, 10.1016/S0022-328X(98)01130-9 Crochet, 1997, Organometallics, 16, 5406, 10.1021/om970513n Bohana, 1998, The five-coordinate hydrido–dihydrogen complex [OsH(η2-H2)(CO)(PiPr3)2]BF4 acting as a template for the carbon–carbon coupling between methyl propiolate and 1,1-diphenyl-2-propyn-1-ol, Organometallics, 17, 373, 10.1021/om970713z Hansen, 2000, Novel ruthenium(II) carbene complexes: products of the reactions of 1-alkynes with (η6-C6Me6)Cl2Ru(PR3), Organometallics, 19, 4740, 10.1021/om0004949 Jiménez-Tenorio, 2004, J Organomet Chem, 689, 2776, 10.1016/j.jorganchem.2004.06.002 Bolaño, 2009, Reactivity of [TpRuCl(PTA)(PPh3)] with alkynes and propargylic alcohols: occurrence of structurally related cationic vs neutral allenylidene complexes with the ruthenium hydrotris(pyrazolyl)borate moiety, Organometallics, 28, 6020, 10.1021/om9005142 Arikawa, 2007, Syntheses of four-membered metallacyclic complexes with nitrosylruthenium and their ring-opening upon HCl addition, Chem Eur J, 13, 4024, 10.1002/chem.200601163 Werner, 1995, Synthesis and reactions of stable 16-electron osmium(0) complexes [OsCl(NO)(PR3)2] including the X-ray crystal structure of [OsCl2(NO)(η1-CH:C:CPh2)(P-i-Pr3)2], Organometallics, 14, 612, 10.1021/om00002a007 Wang, 2020, Redox-neutral propargylic C–H functionalization by using iron catalysis, Synlett, 31, 1747, 10.1055/s-0040-1707271 For examples of stable group 9 metal allenyl complexes, see: (a) Werner H, Kukla F, Steiner P. A new family of organometallic rhodium complexes with [Rh(PiPr2Ph)2] and [Rh(PiPrPh2)2] as molecular units. Eur J Inorg Chem. 2002;2002:1377–1389. Werner, 2002, Unusual pathways for metal-assisted C–C and C–P coupling reactions using allenylidenerhodium complexes as precursors, J Am Chem Soc, 124, 6966, 10.1021/ja012479g Chen, 1997, Coordination of aniline to an (η1-allenyl)iridium complex leading to hydroanilination, Organometallics, 16, 1476, 10.1021/om9602623 Hughes, 2006, Carbon–fluorine bond activation coupled with alkynyl migration to give fluorinated allenyl complexes of iridium, Organometallics, 25, 3943, 10.1021/om0602916 Wiedemann, 1996, Novel C–C and C–C–P coupling reactions using an allenylidenerhodium complex as a precursor, J Am Chem Soc, 118, 2495, 10.1021/ja953911v For examples of stable group 10 metal allenyl complexes, see: (a) Azami H, Tsukada T, Tanifuji R, Seki R, Iwasaki M. Unprecedented formation of 2-aryl-3-oxocyclobut-1-enyl ligand from 3-arylpropargyl chloride, carbon monoxide, and Pd(0) or Pt(0) complex. Chem Lett 2015;44:1550–1551. Blosser, 2001, Slippage of η3-allenyl/propargyl to an η1 structure and tautomerization of η1-propargyl to η1-allenyl in ligand addition and substitution reactions of platinum(II) complexes, Inorg Chim Acta, 320, 110, 10.1016/S0020-1693(01)00493-5 Kim, 2013, Synthesis and structures of η1-allenyl and/or -propargyl Pd(II) complexes and their reactivity toward trimethylsilyl pseudohalides, organic thiols, and N-heterocyclic carbene ligands, Inorg Chim Acta, 398, 54, 10.1016/j.ica.2012.12.011 Canovese, 2015, Oxidative addition of allyl and propargyl halides on palladium(0) complexes bearing bidentate ligands with quinolinic structure, J Organomet Chem, 788, 21, 10.1016/j.jorganchem.2015.01.023 Takahashi, 2008, Mono- and dipalladium movement on the π-conjugated five-carbon chain, Organometallics, 27, 276, 10.1021/om700909k Wouters, 1994, Synthesis of trans-(σ-allenyl)platinum(II) and -palladium(II) compounds. X-ray crystal structure of trans-[PtBr{C(H)=C=CMe2}(PPh3)2] and highly diastereoselective trans-cis isomerization of (σ-allenyl)palladium(II) bromides, Organometallics, 13, 4586, 10.1021/om00023a071 For examples of stable group 11 metal allenyl complexes, see: (a) Johanson A, Laguna A, Gimeno MC. Axially chiral allenyl gold complexes. J Am Chem Soc. 2014;136:12812–12815. 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Rearrangement of (cyclobutenyl)carbene tungsten complexes to 1-tungsta-1,3,5-hexatrienes, Organometallics, 17, 1197, 10.1021/om9708586 Barluenga, 1997, First [4+2] cycloaddition of alkynyl fischer carbene complexes with heterodienes. facile synthesis of 1,4-dihydropyridines from 1-azadienes, Tetrahedron Lett, 38, 3981, 10.1016/S0040-4039(97)00737-5 Aumann, 1994, Organic syntheses via transition metal complexes. 72. (2-(Acyloxy)ethenyl)carbene complexes by Michael addition of carboxylic acids to alkynylcarbene complexes (M = Cr, W). 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Regioselective [C3+C2] cyclopentadiene annulation to enamines with alkynylcarbene complexes of chromium and tungsten as novel C3 building blocks, Organometallics, 15, 5018, 10.1021/om960729+ Aumann, 1994, Homopyrroles by metal-mediated cycloadditions of (NH)-enamines to alkynylcarbene tungsten complexes via 1-metalla-1,3,5-trienes, Synlett, 1041, 10.1055/s-1994-23079 Aumann, 1993, Pyridines via Fischer carbene complexes. W(CO)6-mediated cycloadditions of enamines to alkynes via alkynylcarbene and 1,2-dihydropyridin-2-ylidene complexes, Synlett, 669, 10.1055/s-1993-22566 Aumann, 1993, Metathesis of enamines by alkynylcarbene tungsten complexes. 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