A novel NHC-catalyzed transformation of 2H-chromene-3-carboxaldehydes to 3-methyl-2H-chromen-2-ones.
Nair, Vijay; Sinu, C. R.; Rejithamol, R.; Seetha Lakshmi, K. C.; Suresh, Eringathodi; Organic & biomolecular chemistry 9 (2011) 5511–5514; doi:10.1039/c1ob05325f

data_7151929
_publ_section_title
;
 A novel NHC-catalyzed transformation of 2H-chromene-3-carboxaldehydes
 to 3-methyl-2H-chromen-2-ones.
;
_journal_issue                   15
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              5511
_journal_page_last               5514
_journal_paper_doi               10.1039/c1ob05325f
_journal_volume                  9
_journal_year                    2011
_chemical_formula_sum            'C11 H10 O2'
_chemical_formula_weight         174.19
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_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
_cell_angle_alpha                83.301(7)
_cell_angle_beta                 77.060(7)
_cell_angle_gamma                77.613(7)
_cell_formula_units_Z            2
_cell_length_a                   6.352(3)
_cell_length_b                   7.033(3)
_cell_length_c                   10.437(4)
_cell_measurement_reflns_used    1545
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.80
_cell_measurement_theta_min      2.97
_cell_volume                     442.7(3)
_computing_cell_refinement       'BRUKER SMART'
_computing_data_collection       'BRUKER SMART'
_computing_data_reduction        'BRUKER SAINT'
_computing_molecular_graphics    ORTEP
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_diffrn_measurement_device_type  'BRUKER MART APEX CCD DIFFRACTOMETER'
_diffrn_measurement_method       'OMEGA-PHI SCAN'
_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  0.0254
_diffrn_reflns_av_sigmaI/netI    0.0343
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            3420
_diffrn_reflns_theta_full        25.99
_diffrn_reflns_theta_max         25.99
_diffrn_reflns_theta_min         2.01
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_T_max  0.9920
_exptl_absorpt_correction_T_min  0.9720
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   ' BRUKER SADABS'
_exptl_crystal_colour            COLOURLESS
_exptl_crystal_density_diffrn    1.307
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       PLATES
_exptl_crystal_F_000             184
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.14
_exptl_crystal_size_min          0.09
_refine_diff_density_max         0.235
_refine_diff_density_min         -0.301
_refine_diff_density_rms         0.076
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.061
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     147
_refine_ls_number_reflns         1718
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.061
_refine_ls_R_factor_all          0.0663
_refine_ls_R_factor_gt           0.0602
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0825P)^2^+0.1001P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1584
_refine_ls_wR_factor_ref         0.1636
_reflns_number_gt                1476
_reflns_number_total             1718
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c1ob05325f.txt
_cod_data_source_block           rmr152m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'TRICLINIC' changed to 'triclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from
2010-06-29.

'_exptl_absorpt_correction_type' value 'MULTI-SCAN'
changed to 'multi-scan' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7151929