Regiospecific Synthesis of Bicyclo- and Heterobicyclo-gem-difluorocyclobutenes Using Functionalized Fluoroallenes and a Novel Mo-Catalyzed Intramolecular [2 + 2] Cycloaddition Reaction
Qilong Shen; Gerald B. Hammond; Journal of the American Chemical Society 124 (2002) 6534–6535; doi:10.1021/ja0263893

data_4114863
_publ_section_title
;
 Regiospecific Synthesis of Bicyclo- and
 Heterobicyclo-gem-difluorocyclobutenes Using Functionalized Fluoroallenes
 and a Novel Mo-Catalyzed Intramolecular [2 + 2] Cycloaddition Reaction
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              6534
_journal_page_last               6535
_journal_paper_doi               10.1021/ja0263893
_journal_volume                  124
_journal_year                    2002
_chemical_formula_sum            'C24 H35 F2 N O2 S Si'
_chemical_formula_weight         467.68
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.27600(10)
_cell_length_b                   17.1805(3)
_cell_length_c                   18.2920(3)
_cell_measurement_reflns_used    3246
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      4.08
_cell_volume                     2600.86(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.987
_diffrn_measured_fraction_theta_max 0.987
_diffrn_measurement_device_type  'Nonius Kappa-CCD area detector'
_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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0266
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            5826
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         4.10
_exptl_absorpt_coefficient_mu    0.204
_exptl_absorpt_correction_T_max  0.9228
_exptl_absorpt_correction_T_min  0.7772
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.194
_exptl_crystal_description       Needle
_exptl_crystal_F_000             1000
_exptl_crystal_size_max          1.30
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.40
_refine_diff_density_max         0.314
_refine_diff_density_min         -0.198
_refine_diff_density_rms         0.032
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.09(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.056
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     282
_refine_ls_number_reflns         5826
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.056
_refine_ls_R_factor_all          0.0534
_refine_ls_R_factor_gt           0.0435
_refine_ls_shift/su_max          0.028
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0533P)^2^+0.6422P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1099
_refine_ls_wR_factor_ref         0.1180
_reflns_number_gt                5049
_reflns_number_total             5826
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja0263893_s5.cif
_cod_data_source_block           6f
_cod_database_code               4114863