Diamidocarbenes as versatile and reversible [2 + 1] cycloaddition reagents.
Moerdyk, Jonathan P.; Bielawski, Christopher W.; Nature chemistry 4 (2012) 275–280; doi:10.1038/nchem.1267

data_1508181
_publ_section_title
;
 Diamidocarbenes as versatile and reversible [2 + 1] cycloaddition
 reagents.
;
_journal_issue                   4
_journal_name_full               'Nature chemistry'
_journal_page_first              275
_journal_page_last               280
_journal_paper_doi               10.1038/nchem.1267
_journal_volume                  4
_journal_year                    2012
_chemical_formula_moiety
4,8-dimesityl-6,6-dimethyl-2-(4-nitrophenyl)-1-oxa-4,8-diazaspiro[2.5]octane-5,7-dione
_chemical_formula_sum            'C31 H33 N3 O5'
_chemical_formula_weight         527.60
_chemical_name_common            6MesDACNO2Benzaldehyde
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 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                 93.8000(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   15.9318(6)
_cell_length_b                   14.2492(5)
_cell_length_c                   24.1259(9)
_cell_measurement_temperature    150(2)
_cell_volume                     5464.9(3)
_computing_cell_refinement       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_collection       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_reduction        'CrystalClear (Rigaku Inc., 2008)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.0821
_diffrn_reflns_av_sigmaI/netI    0.0494
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            63095
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         3.01
_exptl_absorpt_coefficient_mu    0.088
_exptl_absorpt_correction_type   none
_exptl_absorpt_process_details   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.283
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       blocks
_exptl_crystal_F_000             2240
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.222
_refine_diff_density_min         -0.256
_refine_diff_density_rms         0.047
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.009
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     719
_refine_ls_number_reflns         9604
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.009
_refine_ls_R_factor_all          0.0835
_refine_ls_R_factor_gt           0.0544
_refine_ls_shift/su_max          0.046
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0632P)^2^+2.9967P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1244
_refine_ls_wR_factor_ref         0.1415
_reflns_number_gt                6927
_reflns_number_total             9604
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            nchem.1267-s8.cif
_cod_data_source_block           DACNO2Benzaldehyde/4b
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      P21/c
_cod_database_code               1508181