NHC-Catalyzed Formal [2+2] Annulations of Allenoates for the Synthesis of Substituted Oxetanes.
Lopez, Susana S.; Jaworski, Ashley A.; Scheidt, Karl A.; The Journal of organic chemistry 83 (2018) 14637–14645; doi:10.1021/acs.joc.8b02464

data_4035673
_publ_section_title
;
 NHC-Catalyzed Formal [2+2] Annulations of Allenoates for the Synthesis of
 Substituted Oxetanes.
;
_journal_issue                   23
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              14637
_journal_page_last               14645
_journal_paper_doi               10.1021/acs.joc.8b02464
_journal_volume                  83
_journal_year                    2018
_chemical_formula_moiety         'C15 H15 F3 O3'
_chemical_formula_sum            'C15 H15 F3 O3'
_chemical_formula_weight         300.27
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2018-03-30
_audit_creation_method
;
Olex2 1.2
(compiled 2017.08.10 svn.r3458 for OlexSys, GUI svn.r5381)
;
_cell_angle_alpha                90
_cell_angle_beta                 100.232(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.8866(7)
_cell_length_b                   7.3687(5)
_cell_length_c                   19.7143(13)
_cell_measurement_reflns_used    9794
_cell_measurement_temperature    100
_cell_measurement_theta_max      68.067
_cell_measurement_theta_min      5.841
_cell_volume                     1413.37(17)
_computing_cell_refinement       'SAINT V8.38A (?, 2016)'
_computing_data_collection       'APEX2 V2014.11-0 (Bruker, 2014)'
_computing_data_reduction        'SAINT V8.38A (?, 2016)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      100
_diffrn_detector_area_resol_mean 8
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device_type  'Bruker Kappa APEX CCD area detector'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_monochromator  'Quazar optics'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0268
_diffrn_reflns_av_unetI/netI     0.0152
_diffrn_reflns_Laue_measured_fraction_full 0.993
_diffrn_reflns_Laue_measured_fraction_max 0.988
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            27431
_diffrn_reflns_point_group_measured_fraction_full 0.993
_diffrn_reflns_point_group_measured_fraction_max 0.988
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.061
_diffrn_reflns_theta_min         4.544
_diffrn_source                   microsource
_exptl_absorpt_coefficient_mu    1.065
_exptl_absorpt_correction_T_max  0.7531
_exptl_absorpt_correction_T_min  0.6762
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'SADABS-2016/2 (Bruker,2016/2) was used for absorption correction. wR2(int) was 0.0807 before and 0.0413 after correction. The Ratio of minimum to maximum transmission is 0.8979. The \l/2 correction factor is Not present.'
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.411
_exptl_crystal_description       irregular
_exptl_crystal_F_000             624
_exptl_crystal_size_max          0.497
_exptl_crystal_size_mid          0.402
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.258
_refine_diff_density_min         -0.236
_refine_diff_density_rms         0.040
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.041
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     192
_refine_ls_number_reflns         2551
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.0292
_refine_ls_R_factor_gt           0.0290
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0299P)^2^+0.6487P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0708
_refine_ls_wR_factor_ref         0.0710
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2518
_reflns_number_total             2551
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo8b02464_si_001.cif
_cod_data_source_block           cx1249
_cod_database_code               4035673
_shelx_shelxl_version_number     2016/6
_shelx_estimated_absorpt_t_max   0.857
_shelx_estimated_absorpt_t_min   0.620
_olex2_refinement_description
;
1. 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
2.a Ternary CH refined with riding coordinates:
 C9(H9)
2.b Secondary CH2 refined with riding coordinates:
 C14(H14A,H14B)
2.c Aromatic/amide H refined with riding coordinates:
 C1(H1), C2(H2), C3(H3), C4(H4), C5(H5), C12(H12)
2.d Idealised Me refined as rotating group:
 C10(H10A,H10B,H10C), C15(H15A,H15B,H15C)
;
_shelx_res_checksum              74728
_shelx_hkl_checksum              77237
_olex2_submission_special_instructions 'No special instructions were received'