Chiral N-heterocyclic carbene catalyzed staudinger reaction of ketenes with imines: highly enantioselective synthesis of N-Boc beta-lactams.
Zhang, Yan-Rong; He, Lin; Wu, Xu; Shao, Pan-Lin; Ye, Song; Organic letters 10 (2008) 277–280; doi:10.1021/ol702759b

data_1504506
_publ_section_title
;
 Chiral N-heterocyclic carbene catalyzed staudinger reaction of ketenes
 with imines: highly enantioselective synthesis of N-Boc beta-lactams.
;
_journal_issue                   2
_journal_name_full               'Organic letters'
_journal_page_first              277
_journal_page_last               280
_journal_paper_doi               10.1021/ol702759b
_journal_volume                  10
_journal_year                    2008
_chemical_formula_moiety         'C22 H24 Cl N O3'
_chemical_formula_sum            'C22 H24 Cl N O3'
_chemical_formula_weight         385.87
_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                 95.53(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   8.0530(16)
_cell_length_b                   13.987(3)
_cell_length_c                   9.3010(19)
_cell_measurement_reflns_used    9830
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.44
_cell_measurement_theta_min      2.20
_cell_volume                     1042.8(4)
_computing_cell_refinement       'Rapid Auto(Rigaku 2001)'
_computing_data_collection       'Rapid Auto(Rigaku 2001)'
_computing_data_reduction        'Rapid Auto(Rigaku 2001)'
_computing_molecular_graphics    'XP in Siemens SHELXTL (Sheldrick, 1994)'
_computing_publication_material  'SHELX97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Rigaku raxis Rapid IP Area Detector'
_diffrn_measurement_method       '\w scans at fixed \c = 45\%'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0307
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            4625
_diffrn_reflns_theta_full        27.44
_diffrn_reflns_theta_max         27.44
_diffrn_reflns_theta_min         2.20
_diffrn_standards_decay_%        none
_exptl_absorpt_coefficient_mu    0.204
_exptl_absorpt_correction_T_max  0.9759
_exptl_absorpt_correction_T_min  0.9701
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'ABSCOR by T.Higashi    8 March, 1995'
_exptl_crystal_density_diffrn    1.229
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             408
_exptl_crystal_size_max          0.15
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.235
_refine_diff_density_min         -0.211
_refine_diff_density_rms         0.044
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.02(6)
_refine_ls_extinction_coef       0.059(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.027
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     245
_refine_ls_number_reflns         4625
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.027
_refine_ls_R_factor_all          0.0470
_refine_ls_R_factor_gt           0.0411
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0649P)^2^+0.1039P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1080
_refine_ls_wR_factor_ref         0.1116
_reflns_number_gt                4095
_reflns_number_total             4625
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol702759b-file001.cif
_cod_data_source_block           2073a
_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 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      P2(1)
_cod_database_code               1504506