Asymmetric synthesis of C2-symmetric vicinal diamines via reductive dimerization of N-acylpyridinium and related salts.
Bharathi, Pandi; Comins, Daniel L.; Organic letters 10 (2008) 221–223; doi:10.1021/ol702595d

data_1504483
_publ_contact_author             'Daniel L. Comins'
_publ_section_title
;
 Asymmetric synthesis of C2-symmetric vicinal diamines via reductive
 dimerization of N-acylpyridinium and related salts.
;
_journal_issue                   2
_journal_name_full               'Organic letters'
_journal_page_first              221
_journal_page_last               223
_journal_paper_doi               10.1021/ol702595d
_journal_volume                  10
_journal_year                    2008
_chemical_formula_sum            'C60 H92 N2 O6 Si2'
_chemical_formula_weight         993.54
_chemical_melting_point          110
_chemical_name_systematic
;(2R,2'R)-4,4'-Dioxo-5,5'-bis-(triisopropylsilanyl)-3,4,3',4'-tetrahydro-
  2H,2'H-['2,2']bipyridinyl-1,1'-dicarboxylic acid bis-[(1S,2R)-
  2-(1-methyl-1-phenylethyl)-cyclohexyl] ester  
;
_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                   13.3273(4)
_cell_length_b                   16.5368(5)
_cell_length_c                   26.0268(7)
_cell_measurement_reflns_used    9722
_cell_measurement_temperature    110
_cell_measurement_theta_max      23.05
_cell_measurement_theta_min      2.19
_cell_volume                     5736.1(3)
_computing_cell_refinement       SAINT
_computing_data_collection       Apex2
_computing_data_reduction        SAINT
_computing_molecular_graphics    NRCVAX
_computing_publication_material  cif2tables.py
_computing_structure_refinement  XL
_computing_structure_solution    SIR92
_diffrn_ambient_temperature      110
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker-Nonius X8 Apex2'
_diffrn_measurement_method       'omega and phi scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0471
_diffrn_reflns_av_sigmaI/netI    0.0249
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            131513
_diffrn_reflns_theta_full        23.74
_diffrn_reflns_theta_max         23.74
_diffrn_reflns_theta_min         1.96
_exptl_absorpt_coefficient_mu    0.112
_exptl_absorpt_correction_T_max  0.9824
_exptl_absorpt_correction_T_min  0.9715
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.150
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             2168
_exptl_crystal_preparation       '1:1 MeOH/Et2O'
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.389
_refine_diff_density_min         -0.411
_refine_diff_density_rms         0.035
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.05(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     647
_refine_ls_number_reflns         8712
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0398
_refine_ls_R_factor_gt           0.0348
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0402P)^2^+2.1457P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0805
_refine_ls_wR_factor_ref         0.0833
_reflns_number_gt                8026
_reflns_number_total             8712
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol702595d-file001.cif
_cod_data_source_block           3
_cod_database_code               1504483