Lewis acid catalyzed [2+2] cycloaddition of ynamides and propargyl silyl ethers: synthesis of alkylidenecyclobutenones and their reactivity in ring-opening and ring expansion.
Chen, Ling; Cao, Jian; Xu, Zheng; Zheng, Zhan-Jiang; Cui, Yu-Ming; Xu, Li-Wen; Chemical communications (Cambridge, England) 52 (2016) 9574–9577; doi:10.1039/c6cc04648g

data_7124786
_publ_section_title
;
 Lewis acid catalyzed [2+2] cycloaddition of ynamides and propargyl silyl
 ethers: synthesis of alkylidenecyclobutenones and their reactivity in
 ring-opening and ring expansion.
;
_journal_issue                   61
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              9574
_journal_page_last               9577
_journal_paper_doi               10.1039/c6cc04648g
_journal_volume                  52
_journal_year                    2016
_chemical_formula_sum            'C29 H20 O'
_chemical_formula_weight         384.45
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2016-01-10 deposited with the CCDC.
2016-07-04 downloaded from the CCDC.
;
_cell_angle_alpha                114.389(2)
_cell_angle_beta                 96.569(3)
_cell_angle_gamma                105.237(2)
_cell_formula_units_Z            2
_cell_length_a                   9.5812(12)
_cell_length_b                   10.2719(13)
_cell_length_c                   12.371(2)
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      27.20
_cell_measurement_theta_min      2.47
_cell_volume                     1034.9(3)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0265
_diffrn_reflns_av_sigmaI/netI    0.0310
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            10951
_diffrn_reflns_theta_full        25.20
_diffrn_reflns_theta_max         25.20
_diffrn_reflns_theta_min         1.87
_exptl_absorpt_coefficient_mu    0.073
_exptl_absorpt_correction_T_max  0.984
_exptl_absorpt_correction_T_min  0.977
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.234
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             404
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.27
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.145
_refine_diff_density_min         -0.161
_refine_diff_density_rms         0.029
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.027
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     271
_refine_ls_number_reflns         3697
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.027
_refine_ls_R_factor_all          0.0543
_refine_ls_R_factor_gt           0.0384
_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^)+(0.0550P)^2^+0.1831P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1027
_refine_ls_wR_factor_ref         0.1141
_reflns_number_gt                2834
_reflns_number_total             3697
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c6cc04648g2.cif
_cod_data_source_block           20141112c
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_exptl_absorpt_correction_type' value 'Multi-scan' was
changed to 'multi-scan' in accordance with the
/home/saulius/struct/COD-crude-data/automatic-downloads/DataCite-retrospective/RSC/depositions/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

data item '_symmetry_cell_setting' value 'Triclinic' was changed to
'triclinic' in accordance with the
/home/saulius/struct/COD-crude-data/automatic-downloads/DataCite-retrospective/RSC/depositions/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

Automatic conversion script
Id: cif_fix_values 6909 2019-04-08 15:41:33Z antanas 
;
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7124786