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Chiral Ligands On A Spiro Scaffold for Transition-Metal-Catalyzed Asymmetric Reactions Work by Prof. Zhou Qi-Lin. Ye Zhu 09/02/10 Burgess’s Group Meeting. Ubiquitous Spirocyclic Framework.
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Chiral Ligands On A Spiro Scaffold for Transition-Metal-Catalyzed Asymmetric Reactions Work by Prof. Zhou Qi-Lin Ye Zhu 09/02/10 Burgess’s Group Meeting
Ubiquitous Spirocyclic Framework in 1900, von Baeyer introduced the name “spirocyclane” for bicyclic hydrocarbons having two rings with a common carbon atom (spiro carbon) the two rings of the spiro compounds lie in perpendicular planes, which not only gives rise to an axial chirality in spiro compounds having substituents on the rings but also increases molecular rigidity the spirocyclic framework is considerably more rigid than that of biaryls, since conformational changes involve distortion of the entire molecule racemization of chiral spiro compounds virtually impossible very few applications despite these excellent characteristics
Spiro[4,4]nonane-1,6-diol As Chiral Auxiliaries in the Reduction of Ketones Kumar, A., et al, Chem. Commun. 1992, 493. 2 eq. (+) 1, 2 eq. LAH, -80 °C, 80%, 98% ee 2 eq. (+) 1, 2 eq. LAH, -20 °C, 75%, 89% ee
Spiro[4,4]nonane-1,6-diol As Chiral Auxiliaries in the Reduction of Ketones Kumar, A., et al, Chem. Commun. 1992, 493. 2 eq. (+) 1, 2 eq. LAH, -80 °C, 80%, 98% ee 2 eq. (+) 1, 2 eq. LAH, -20 °C, 75%, 89% ee
Monodentate SpiroPhosphoramidite Ligand Xumu, Zhang, et al, Org. Lett. 2004, 3565.
Synthesis of Chiral Monodentate Spiro Ligand via9,9’-Spirobixanthene-1,1’-Diol Xumu, Zhang, et al, Org. Lett. 2004, 3565.
Synthesis of 1,1’Spirobiindane-7,7’-diol Birman, V.B., et al, Tetrahedron Asymmetry1999, 125.
Synthesis of 1,1’Spirobiindane-7,7’-diol Birman, V.B., et al, Tetrahedron Asymmetry1999, 125.
Highly efficient and practical resolution of1,1-spirobiindane-7,7-diol by inclusion crystallization withN-benzylcinchonidinium chloride A highly efficient and practical resolution of racemic 1,1-spirobiindane-7,7-diol (±)-1 has been achieved, with the (S)-(−)- and (R)-(+)-forms of 1 obtained with >99% e.e. in 82% yield from the inclusion complex and 75% yield from the mother liquor, respectively Zhou, Qi-Lin, et al, Tetrahedron Asymmetry2002, 1363.
Synthesis of 9,9’-Spirobifluorene-1,1’-diol Zhou, Qi-lin, et al,
Synthesis of 9,9’-Spirobifluorene-1,1’-diol SBIFOL was conveniently synthesized from 1,2-dibromobenzene and 3-bromoanisole in high yield. Both enantiomers of SBIFOL were obtained in 99% ee by inclusion resolution with 2,3-dimethoxy-N,N,N’,N’ tetracyclohexylsuccinamide
Synthesis of SDP Ligands Zhou, Qi-Lin, et al, J. Am.Chem.Soc., 2003, 4404.
Zhou, Q.-L. et al, Angew. Chem., Int. Ed. 2002, 41, 2348. Zhou, Q.-L. et al, Org. Lett. 2006, 8, 1479. Zhou, Q.-L. et al, J. Org. Chem. 2004, 69, 8157. Zhou, Q.-L. et al, J. Am.Chem. Soc. 2006, 128, 11774. Zhou, Q.-L. et al, Org. Lett. 2005, 7, 2333. Zhou, Qi-Lin, et al, Angew. Chem. Int. Ed., 2005, 1118.
Synthesis of Chiral Spiro Phosphine-Oxazoline Ligands Zhou, Q.-L. et al, J. Am.Chem. Soc. 2006, 128, 12886.
Applications: Asymmetric Hydrogenation Zhou, Q.-L. et al, J. Am. Chem. Soc. 2006, 128, 11774 ketones a new chiral scaffold and their application in the ruthenium- catalyzed asymmetric hydrogenation of simple ketones with high activity (S/C up to 100 000) and excellent enantioselectivity (ee up to 99.5%)
Highly Enantioselective and Diastereoselective Synthesis of Chiral Amino Alcohols Zhou, Qi-Lin, et al, J. Am. Chem. Soc., 2010, 4222.
Enantioselective Hydrogenation of α-Arylmethylene Cycloalkanones the asymmetric hydrogenation of exocyclic α,β-unsaturated ketones is a challenge task Zhou, Qi-Lin, et al, J. Am. Chem. Soc., 2010, 4538.
Applications: Asymmetric Hydrogenation Zhou, Q.-L. et al, J. Am. Chem. Soc. 2007, 129, 1868 aldehydes the first example of asymmetric hydrogenation of aldehyde via DKR
Applications: Asymmetric Hydrogenation Zhou, Q.-L. et al, Angew. Chem. Int.Ed. 2005, 1118 α,β-unsaturated carboxylic acid these results are comparable to, or better than, those obtained with [Ru(OAc)2(binap)] and other catalysts
Applications: Asymmetric Hydrogenation Zhou, Q.-L. et al, Angew. Chem. Int.Ed. 2005, 1118 α,β-unsaturated carboxylic acid these results represents the highest level of enantiocontrol reported to date in the asymmetric hydrogenation of cinnamic acid derivatives
Applications: Asymmetric Hydrogenation Zhou, Q.-L. et al, Adv. Synth, Catal. 2006, 1271 α,β-unsaturated carboxylic acid
Hydrogenations with Chiral Spiro Phosphine-Oxazoline Ligands Zhou, Q.-L. et al, J. Am. Chem. Soc. 2008, 130, 8584. Zhou, Q.-L. et al, J. Am. Chem. Soc. 2010, 132, 1172. Zhou, Q.-L. et al, J. Am. Chem. Soc. 2006, 128, 12886.
Applications: Asymmetric Hydrogenation Zhou, Q.-L. et al, J. Am. Chem. Soc. 2006, 128, 11774 Other ligands such as the diphosphine ligands BINAP, Josiphos, and SDP (6a) and the monodentate phosphorus ligands Mono- Phos, H-MOP, SIPHOS (9a), and ShiP (10a) provided the hydrogenation product with very low enantioselectivities under the same reaction conditions
Iridium-Catalyzed Asymmetric Hydrogenation of Cyclic Enamines Zhou, Qi-Lin, et al, J. Am. Chem. Soc., 2010, 1366.
Enantioselective Iron-catalysed O–H Bond Insertions Zhou, Qi-Lin, et al, Natural Chemistry, 2010, 546.
Other Developments Zhou, Qi-Lin, et al, J. Am. Chem. Soc., 2007, 5834. Enantioselective Insertion of Carbenoids into N−H Bonds Catalyzed by Copper Complexes of Chiral Spiro Bisoxazolines Zhou, Qi-Lin, et al, Angew. Chem. Int. Ed., 2008, 932. Enantioselective Synthesis of a-Hydroxyesters by a Copper–Carbenoid O-H Insertion Reaction
Other Developments Zhou, Qi-Lin, et al, Angew. Chem. Int. Ed., 2008, 8496. Copper-Catalyzed Highly Enantioselective Carbenoid Insertion into Si-H Bonds Zhou, Qi-Lin, et al, Angew. Chem. Int. Ed., 2008, 4351. Enantioselective Rhodium-Catalyzed Addition of Arylboronic Acids to β-Ketoesters
Addition of Arylboronic Acids to Aldehydes and N-Tosylarylimines
Ni Catalyzed Reactions Zhou, Qi-Lin, et al, J. Am. Chem. Soc., 2010, 10955. Enantioselective Nickel-Catalyzed Reductive Coupling of Alkynes and Imines Zhou, Qi-Lin, et al, J. Am. Chem. Soc., 2008, 14052. Enantioselective Nickel-Catalyzed Alkylative Coupling of Alkynes and Aldehydes
Asymmetric hydrovinylat-ion of Vinylarenes Zhou, Q.-L. et al, J. Am. Chem. Soc. 2006, 128, 2780
Pd Catalyzed Carboamination Reactions John, Wolfe, et al, J. Am. Chem. Soc. 2010, 12157.