Tuning efficiency of the 4-exo-trig cyclization by the electronic effect: ring closure of 3,3-difluoro-4-pentenyl carbon radicals and synthesis of a gem-difluorocyclobutane nucleoside
Hiroki Kumamoto; Sachiko Kawahigashi; Hiromi Wakabayashi; Tomohiko Nakano; Tomoko Miyaike; Yasuyuki Kitagawa; Hiroshi Abe; Mika Ito; Kazuhiro Haraguchi; Jan Balzarini; Masanori Baba; Hiromichi Tanaka; Chem.Commun. 48 (2012) 10993–; doi:10.1039/c2cc35876j

data_7108542
_publ_section_title
;
 Tuning efficiency of the 4-exo-trig cyclization by the electronic effect:
 ring closure of 3,3-difluoro-4-pentenyl carbon radicals and synthesis of
 a gem-difluorocyclobutane nucleoside
;
_journal_name_full               Chem.Commun.
_journal_page_first              10993
_journal_paper_doi               10.1039/c2cc35876j
_journal_volume                  48
_journal_year                    2012
_chemical_formula_moiety         'C11 H14 F2 N2 O4'
_chemical_formula_sum            'C11 H14 F2 N2 O4'
_chemical_formula_weight         276.24
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      15
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.0000
_cell_angle_beta                 91.934(15)
_cell_angle_gamma                90.0000
_cell_formula_units_Z            8
_cell_length_a                   19.14(3)
_cell_length_b                   6.288(9)
_cell_length_c                   19.81(3)
_cell_measurement_reflns_used    1529
_cell_measurement_temperature    93
_cell_measurement_theta_max      27.50
_cell_measurement_theta_min      3.40
_cell_volume                     2383(6)
_computing_cell_refinement       'CrystalClear-SM Expert 2.0 r7'
_computing_data_collection       'CrystalClear-SM Expert 2.0 r7 (Rigaku, 2011)'
_computing_data_reduction        'CrystalClear-SM Expert 2.0 r7'
_computing_molecular_graphics    'CrystalStructure 4.0'
_computing_publication_material  'CrystalStructure 4.0 (Rigaku, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'Il Milione (Burla, et al., 2007)'
_diffrn_ambient_temperature      93
_diffrn_detector_area_resol_mean 6.827
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Rigaku XtaLAB mini'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0316
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -4
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            5048
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.137
_exptl_absorpt_correction_T_max  0.982
_exptl_absorpt_correction_T_min  0.879
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'REQAB (Rigaku, 1998)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.540
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1152.00
_exptl_crystal_size_max          0.340
_exptl_crystal_size_mid          0.210
_exptl_crystal_size_min          0.130
_refine_diff_density_max         0.840
_refine_diff_density_min         -0.500
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.144
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     175
_refine_ls_number_reflns         2210
_refine_ls_number_restraints     0
_refine_ls_R_factor_gt           0.0473
_refine_ls_shift/su_max          0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0742P)^2^+5.7241P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1596
_reflns_number_gt                1843
_reflns_number_total             2211
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            c2cc35876j.txt
_cod_data_source_block           sc0921
_cod_original_cell_volume        2383(7)
_cod_database_code               7108542