A concise route to pyridines from hydrazides by metal carbene N-H insertion, 1,2,4-triazine formation, and Diels-Alder reaction.
Shi, Baolu; Lewis, William; Campbell, Ian B.; Moody, Christopher J.; Organic letters 11 (2009) 3686–3688; doi:10.1021/ol901502u

data_1504101
_publ_section_title
;
 A concise route to pyridines from hydrazides by metal carbene N-H
 insertion, 1,2,4-triazine formation, and Diels-Alder reaction.
;
_journal_issue                   16
_journal_name_full               'Organic letters'
_journal_page_first              3686
_journal_page_last               3688
_journal_paper_doi               10.1021/ol901502u
_journal_volume                  11
_journal_year                    2009
_chemical_formula_moiety         'C12 H11 N3 O2'
_chemical_formula_sum            'C12 H11 N3 O2'
_chemical_formula_weight         229.24
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_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                 92.508(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.5084(8)
_cell_length_b                   8.3001(9)
_cell_length_c                   17.5331(19)
_cell_measurement_reflns_used    3121
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      27.60
_cell_measurement_theta_min      2.33
_cell_volume                     1091.6(2)
_computing_cell_refinement       'Bruker SAINT version 6.36A (Bruker, 2002)'
_computing_data_collection       'Bruker SMART version 5.625 (Bruker, 2001)'
_computing_data_reduction        'Bruker SAINT; SHELXTL (Sheldrick, 2008)'
_computing_molecular_graphics    ' ?'
_computing_publication_material  'enCIFer(Allen et al.,2004);PLATON(Spek,2003)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 8.366
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0295
_diffrn_reflns_av_sigmaI/netI    0.0261
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            6599
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.60
_diffrn_reflns_theta_min         2.33
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.098
_exptl_absorpt_correction_T_max  0.969
_exptl_absorpt_correction_T_min  0.852
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS 2007/2'
_exptl_crystal_colour            YELLOW
_exptl_crystal_density_diffrn    1.395
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       BLOCK
_exptl_crystal_F_000             480
_exptl_crystal_size_max          0.65
_exptl_crystal_size_mid          0.61
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.395
_refine_diff_density_min         -0.275
_refine_diff_density_rms         0.061
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.039
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     156
_refine_ls_number_reflns         2526
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.039
_refine_ls_R_factor_all          0.0501
_refine_ls_R_factor_gt           0.0456
_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^)+(0.0791P)^2^+0.1973P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1238
_refine_ls_wR_factor_ref         0.1283
_reflns_number_gt                2245
_reflns_number_total             2526
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            ol901502u_si_002.cif
_cod_data_source_block           ph124a
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               1504101