Enantioselective Synthesis of α,α-Disubstituted Cyclopentenes by an N-Heterocyclic Carbene-Catalyzed Desymmetrization of 1,3-Diketones
Manabu Wadamoto; Eric M. Phillips; Troy E. Reynolds; Karl A. Scheidt; Journal of the American Chemical Society 129 (2007) 10098–10099; doi:10.1021/ja073987e

data_4109802
_publ_section_title
;
 Enantioselective Synthesis of \a,\a-Disubstituted Cyclopentenes by an
 N-Heterocyclic Carbene-Catalyzed Desymmetrization of 1,3-Diketones
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              10098
_journal_page_last               10099
_journal_paper_doi               10.1021/ja073987e
_journal_volume                  129
_journal_year                    2007
_chemical_formula_sum            'C11 H13 O3'
_chemical_formula_weight         193.21
_chemical_name_common            'Tricyclic Lactone'
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.286(5)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.765(2)
_cell_length_b                   18.967(6)
_cell_length_c                   7.707(2)
_cell_measurement_reflns_used    3617
_cell_measurement_temperature    153(2)
_cell_measurement_theta_max      27.84
_cell_measurement_theta_min      2.64
_cell_volume                     988.9(5)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      153(2)
_diffrn_measured_fraction_theta_full 0.924
_diffrn_measured_fraction_theta_max 0.924
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1031
_diffrn_reflns_av_sigmaI/netI    0.1106
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            9008
_diffrn_reflns_theta_full        28.83
_diffrn_reflns_theta_max         28.83
_diffrn_reflns_theta_min         2.15
_exptl_absorpt_coefficient_mu    0.094
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.298
_exptl_crystal_description       block
_exptl_crystal_F_000             412
_exptl_crystal_size_max          0.284
_exptl_crystal_size_mid          0.120
_exptl_crystal_size_min          0.114
_refine_diff_density_max         0.562
_refine_diff_density_min         -0.575
_refine_diff_density_rms         0.138
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   4(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.655
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     261
_refine_ls_number_reflns         4508
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.655
_refine_ls_R_factor_all          0.1871
_refine_ls_R_factor_gt           0.1608
_refine_ls_shift/su_max          2.730
_refine_ls_shift/su_mean         0.100
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.4399
_refine_ls_wR_factor_ref         0.4531
_reflns_number_gt                3176
_reflns_number_total             4508
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja073987esi20070615_113846.cif
_cod_data_source_block           s07wm
_cod_original_cell_volume        988.8(5)
_cod_database_code               4109802