Tethered Tungsten-Alkylidenes for the Synthesis of Cyclic Polynorbornene via Ring Expansion Metathesis: Unprecedented Stereoselectivity and Trapping of Key Catalytic Intermediates.
Jakhar, Vineet; Pal, Digvijayee; Ghiviriga, Ion; Abboud, Khalil A.; Lester, Daniel W.; Sumerlin, Brent S.; Veige, Adam S.; Journal of the American Chemical Society 143 (2021) 1235–1246; doi:10.1021/jacs.0c12248

data_4135566
_publ_section_title
;
 Tethered Tungsten-Alkylidenes for the Synthesis of Cyclic Polynorbornene
 via Ring Expansion Metathesis: Unprecedented Stereoselectivity and
 Trapping of Key Catalytic Intermediates.
;
_journal_issue                   2
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              1235
_journal_page_last               1246
_journal_paper_doi               10.1021/jacs.0c12248
_journal_volume                  143
_journal_year                    2021
_chemical_formula_moiety         'C42 H55 N O4 W, 0.5 (C6 H6)'
_chemical_formula_sum            'C45 H58 N O4 W'
_chemical_formula_weight         860.77
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2018-08-28 # Formatted by publCIF

;
_cell_angle_alpha                90
_cell_angle_beta                 96.9729(7)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.3427(4)
_cell_length_b                   33.5187(13)
_cell_length_c                   11.3695(4)
_cell_measurement_reflns_used    9470
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      33.82
_cell_measurement_theta_min      2.18
_cell_volume                     3912.4(3)
_computing_cell_refinement       'Bruker APEX3 (Bruker, 2014)'
_computing_data_collection       'Bruker APEX3 (Bruker, 2014)'
_computing_data_reduction        'Bruker Apex3 SAINT (Bruker, 2014)'
_computing_molecular_graphics    'XP in SHELXTL-plus, Bruker 2014'
_computing_publication_material  'SHELXL2014/7, Sheldrick, G. M. 2014'
_computing_structure_refinement  'SHELXL2014/7, Sheldrick G. M. 2014'
_computing_structure_solution    'SHELXL2014/7, Sheldrick G. M. 2014'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.921
_diffrn_measurement_device_type  'Bruker APEX-II DUO'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0316
_diffrn_reflns_av_unetI/netI     0.0289
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.921
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       50
_diffrn_reflns_limit_k_min       -50
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            104011
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.921
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         34.056
_diffrn_reflns_theta_min         1.215
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    2.996
_exptl_absorpt_correction_T_max  0.9144
_exptl_absorpt_correction_T_min  0.6741
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details
'based on measured indexed crystal faces, Bruker SHELXTL2014 (Sheldrick, 2014)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.461
_exptl_crystal_description       plate
_exptl_crystal_F_000             1764
_exptl_crystal_size_max          0.212
_exptl_crystal_size_mid          0.053
_exptl_crystal_size_min          0.048
_refine_diff_density_max         1.217
_refine_diff_density_min         -2.200
_refine_diff_density_rms         0.096
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.125
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     469
_refine_ls_number_reflns         14754
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.125
_refine_ls_R_factor_all          0.0310
_refine_ls_R_factor_gt           0.0216
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0212P)^2^+1.2193P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0430
_refine_ls_wR_factor_ref         0.0499
_reflns_Friedel_coverage         0.000
_reflns_number_gt                12518
_reflns_number_total             14754
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja0c12248_si_003.cif
_cod_data_source_block           vj11
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4135566
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.569
_shelx_estimated_absorpt_t_max   0.870
_shelx_res_checksum              30822
_shelx_hkl_checksum              77194