Catalyst-Free Synthesis of 2,3-Dihydrobenzofurans via a Formal [4+1] Annulation of Propargylamines with Sulfur Ylides.
He, Xinwei; Xie, Mengqing; Tang, Qiang; Zuo, Youpeng; Li, Ruxue; Shang, Yongjia; The Journal of organic chemistry 84 (2019) 11623–11638; doi:10.1021/acs.joc.9b01557

data_4034511
_publ_section_title
;
 Catalyst-Free Synthesis of 2,3-Dihydrobenzofurans via a Formal [4+1]
 Annulation of Propargylamines with Sulfur Ylides.
;
_journal_issue                   18
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              11623
_journal_page_last               11638
_journal_paper_doi               10.1021/acs.joc.9b01557
_journal_volume                  84
_journal_year                    2019
_chemical_formula_sum            'C21 H15 Br O2'
_chemical_formula_weight         379.24
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_cell_angle_beta                 75.096(2)
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_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.38
_cell_measurement_theta_min      2.26
_cell_volume                     836.1(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
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_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2018/1 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.970
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
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_diffrn_reflns_av_R_equivalents  0.0286
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_diffrn_reflns_Laue_measured_fraction_full 0.989
_diffrn_reflns_Laue_measured_fraction_max 0.970
_diffrn_reflns_limit_h_max       10
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_diffrn_reflns_point_group_measured_fraction_full 0.989
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_diffrn_reflns_theta_max         27.443
_diffrn_reflns_theta_min         1.746
_exptl_absorpt_coefficient_mu    2.468
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.506
_exptl_crystal_description       block
_exptl_crystal_F_000             384
_refine_diff_density_max         0.499
_refine_diff_density_min         -0.639
_refine_diff_density_rms         0.072
_refine_ls_extinction_method     none
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_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         3705
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.092
_refine_ls_R_factor_all          0.0718
_refine_ls_R_factor_gt           0.0534
_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^)+(0.0301P)^2^+1.6629P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1218
_refine_ls_wR_factor_ref         0.1309
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2910
_reflns_number_total             3705
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo9b01557_si_003.cif
_cod_data_source_block           181219a_0m
_cod_database_code               4034511
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