Metal-Free Visible Light-Mediated Photocatalysis: Controlling Intramolecular [2 + 2] Photocycloaddition of Enones through Axial Chirality.
Clay, Anthony; Vallavoju, Nandini; Krishnan, Retheesh; Ugrinov, Angel; Sivaguru, Jayaraman; The Journal of organic chemistry 81 (2016) 7191–7200; doi:10.1021/acs.joc.6b01066

data_4036952
_publ_section_title
;
 Metal-Free Visible Light-Mediated Photocatalysis: Controlling
 Intramolecular [2 + 2] Photocycloaddition of Enones through Axial
 Chirality.
;
_journal_issue                   16
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              7191
_journal_page_last               7200
_journal_paper_doi               10.1021/acs.joc.6b01066
_journal_volume                  81
_journal_year                    2016
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C22 H27 N O4'
_chemical_formula_sum            'C22 H27 N O4'
_chemical_formula_weight         369.44
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2016-04-29
_audit_creation_method
;
Olex2 1.2
(compiled 2016.02.19 svn.r3266 for OlexSys, GUI svn.r5155)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.9328(3)
_cell_length_b                   14.3352(5)
_cell_length_c                   16.9365(7)
_cell_measurement_reflns_used    9891
_cell_measurement_temperature    103(2)
_cell_measurement_theta_max      66.570
_cell_measurement_theta_min      4.040
_cell_volume                     1925.99(13)
_computing_cell_refinement       'SAINT v8.34A (Bruker, 2013)'
_computing_data_reduction        'SAINT v8.34A (Bruker, 2013)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL (Sheldrick, 2008)'
_diffrn_ambient_temperature      102.74
_diffrn_measured_fraction_theta_full 0.987
_diffrn_measured_fraction_theta_max 0.987
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0246
_diffrn_reflns_av_unetI/netI     0.0228
_diffrn_reflns_Laue_measured_fraction_full 0.987
_diffrn_reflns_Laue_measured_fraction_max 0.987
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            12198
_diffrn_reflns_point_group_measured_fraction_full 0.989
_diffrn_reflns_point_group_measured_fraction_max 0.989
_diffrn_reflns_theta_full        66.565
_diffrn_reflns_theta_max         66.565
_diffrn_reflns_theta_min         4.040
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.703
_exptl_absorpt_correction_T_max  0.7528
_exptl_absorpt_correction_T_min  0.7074
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2014/2 (Bruker,2014/2) was used for absorption correction.
wR2(int) was 0.0621 before and 0.0401 after correction.
The Ratio of minimum to maximum transmission is 0.9397.
The \l/2 correction factor is 0.00150.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.274
_exptl_crystal_description       irregular
_exptl_crystal_F_000             792
_exptl_crystal_size_max          0.29
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.127
_refine_diff_density_min         -0.177
_refine_diff_density_rms         0.035
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   0.60(19)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.073
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     251
_refine_ls_number_reflns         3295
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.073
_refine_ls_R_factor_all          0.0266
_refine_ls_R_factor_gt           0.0261
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0343P)^2^+0.3713P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0660
_refine_ls_wR_factor_ref         0.0663
_reflns_Friedel_coverage         0.736
_reflns_Friedel_fraction_full    0.992
_reflns_Friedel_fraction_max     0.992
_reflns_number_gt                3245
_reflns_number_total             3295
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo6b01066_si_002.cif
_cod_data_source_block           cc-2d_rot
_cod_database_code               4036952
_shelx_estimated_absorpt_t_max   0.884
_shelx_estimated_absorpt_t_min   0.822
_olex2_refinement_description
;
1. Twinned data refinement
 Scales: 0.40(19) 0.60(19)
2. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
3.a Ternary CH refined with riding coordinates:
 C6(H6)
3.b Secondary CH2 refined with riding coordinates:
 C4(H4A,H4B), C11(H11A,H11B)
3.c Aromatic/amide H refined with riding coordinates:
 C18(H18), C19(H19), C20(H20), C21(H21)
3.d Idealised Me refined as rotating group:
 C26(H26A,H26B,H26C), C12(H12A,H12B,H12C), C24(H24A,H24B,H24C), C25(H25A,H25B,
 H25C), C27(H27A,H27B,H27C), C13(H13A,H13B,H13C)
;
_shelx_res_checksum              77080
_shelx_hkl_checksum              86623
_shelx_shelxl_version_number     2014/7
_olex2_submission_special_instructions 'No special instructions were received'