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_7124788
_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 H22 O2'
_chemical_formula_weight         402.47
_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                109.873(2)
_cell_angle_beta                 101.743(2)
_cell_angle_gamma                90.448(2)
_cell_formula_units_Z            2
_cell_length_a                   8.5465(17)
_cell_length_b                   11.111(2)
_cell_length_c                   12.403(3)
_cell_measurement_reflns_used    2697
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      25.77
_cell_measurement_theta_min      2.44
_cell_volume                     1080.7(4)
_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 0.995
_diffrn_measured_fraction_theta_max 0.995
_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  0.0181
_diffrn_reflns_av_sigmaI/netI    0.0299
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            7520
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.14
_exptl_absorpt_coefficient_mu    0.076
_exptl_absorpt_correction_T_max  0.981
_exptl_absorpt_correction_T_min  0.977
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.237
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             424
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.140
_refine_diff_density_min         -0.192
_refine_diff_density_rms         0.048
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     280
_refine_ls_number_reflns         3795
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0567
_refine_ls_R_factor_gt           0.0408
_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^)+(0.0608P)^2^+0.0770P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1010
_refine_ls_wR_factor_ref         0.1111
_reflns_number_gt                2931
_reflns_number_total             3795
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c6cc04648g2.cif
_cod_data_source_block           mo51224a
_cod_depositor_comments
;
The following automatic conversions were performed:

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               7124788