Synthesis of 2,4-Disubstituted Piperidines via Radical Cyclization: Unexpected Enhancement in Diastereoselectivity with Tris(trimethylsilyl)silane
Lucile A. Gandon; Alexander G. Russell; Tatyana Güveli; Angela E. Brodwolf; Benson M. Kariuki; Neil Spencer; John S. Snaith; Journal of Organic Chemistry 71 (2006) 5198–5207; doi:10.1021/jo060495w

data_4021781
_publ_contact_author
;
J.S. Snaith,
School of Chemistry,
University of Birmingham,
Edgbaston, Birmingham, B15 2TT, UK
;
_publ_contact_author_email       j.s.snaith@bham.ac.uk
_publ_section_title
;
 Synthesis of 2,4-Disubstituted Piperidines via Radical Cyclization:
 Unexpected Enhancement in Diastereoselectivity with
 Tris(trimethylsilyl)silane
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              5198
_journal_page_last               5207
_journal_paper_doi               10.1021/jo060495w
_journal_volume                  71
_journal_year                    2006
_chemical_formula_sum            'C21 H25 N O4 S'
_chemical_formula_weight         387.48
_space_group_IT_number           18
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2bc 2'
_symmetry_space_group_name_H-M   'P 2 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                   5.7186(3)
_cell_length_b                   11.3015(5)
_cell_length_c                   32.3981(16)
_cell_measurement_temperature    298(2)
_cell_volume                     2093.85(18)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.987
_diffrn_measured_fraction_theta_max 0.987
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0348
_diffrn_reflns_av_sigmaI/netI    0.0381
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       38
_diffrn_reflns_limit_l_min       -38
_diffrn_reflns_number            13318
_diffrn_reflns_theta_full        70.41
_diffrn_reflns_theta_max         70.41
_diffrn_reflns_theta_min         2.73
_exptl_absorpt_coefficient_mu    1.579
_exptl_absorpt_correction_T_max  0.9112
_exptl_absorpt_correction_T_min  0.5058
_exptl_crystal_density_diffrn    1.229
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             824
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.06
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.283
_refine_diff_density_min         -0.230
_refine_diff_density_rms         0.036
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.02(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.029
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     246
_refine_ls_number_reflns         3889
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.029
_refine_ls_R_factor_all          0.0566
_refine_ls_R_factor_gt           0.0421
_refine_ls_shift/su_max          0.005
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0574P)^2^+0.3214P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1056
_refine_ls_wR_factor_ref         0.1150
_reflns_number_gt                3130
_reflns_number_total             3889
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo060495wsi20060307_104016.cif
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
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_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      'P 2 21 2'
_cod_database_code               4021781