Divergence in the reactivity between amine- and phosphine-catalyzed cycloaddition reactions of allenoates with enynals: one-pot gold-catalyzed synthesis of trisubstituted benzofurans from the [3 + 2] cycloadduct via 1,2-alkyl migration and dehydrogenation.
Kumari, A. Leela Siva; Swamy, K. C. Kumara; The Journal of organic chemistry 80 (2015) 4084–4096; doi:10.1021/acs.joc.5b00415

data_4036179
_publ_section_title
;
 Divergence in the reactivity between amine- and phosphine-catalyzed
 cycloaddition reactions of allenoates with enynals: one-pot
 gold-catalyzed synthesis of trisubstituted benzofurans from the [3 + 2]
 cycloadduct via 1,2-alkyl migration and dehydrogenation.
;
_journal_issue                   8
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              4084
_journal_page_last               4096
_journal_paper_doi               10.1021/acs.joc.5b00415
_journal_volume                  80
_journal_year                    2015
_chemical_formula_sum            'C23 H20 O3'
_chemical_formula_weight         344.39
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 104.297(11)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.8106(11)
_cell_length_b                   8.1876(9)
_cell_length_c                   19.816(3)
_cell_measurement_reflns_used    1438
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      24.9280
_cell_measurement_theta_min      3.0640
_cell_volume                     1856.9(4)
_computing_cell_refinement       'CrysAlisPro, Oxford Diffraction Ltd.'
_computing_data_collection       'CrysAlisPro, Oxford Diffraction Ltd.'
_computing_data_reduction        'CrysAlisPro, Oxford Diffraction Ltd.'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Xcalibur, Eos, Gemini'
_diffrn_measurement_method       '\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  0.0298
_diffrn_reflns_av_sigmaI/netI    0.0449
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            6988
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         3.06
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count 'not applicable'
_diffrn_standards_interval_time  'not applicable'
_diffrn_standards_number         'not applicable'
_exptl_absorpt_coefficient_mu    0.081
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.86268
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrysAlisPro, Oxford Diffraction Ltd.'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.232
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       blocks
_exptl_crystal_F_000             728
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.282
_refine_diff_density_min         -0.172
_refine_diff_density_rms         0.034
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.963
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     240
_refine_ls_number_reflns         3263
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.963
_refine_ls_R_factor_all          0.1013
_refine_ls_R_factor_gt           0.0599
_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^)+(0.0923P)^2^+0.3833P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1565
_refine_ls_wR_factor_ref         0.1865
_reflns_number_gt                1986
_reflns_number_total             3263
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo5b00415_si_002.cif
_cod_data_source_block           compd-15aa
_cod_database_code               4036179