Synthesis of 1,3-diols
C-H functionalization of benzyl silyl ethers by means of rhodium-catalyzed insertions of aryldiazoacetates can be achieved in a highly diastereoselective and enantioselective manner by judicious choice of chiral catalyst or auxiliary. The use of (S)-lactate as a chiral auxiliary resulted in C-H functionalization with moderate diastereoselectivity and enantioselectivity. The best results were achieved using Hashimoto's Rh2((S)-PTTL)4 catalyst.
H. M. L. Davies, S. J. Hedley, B. R. Bohall, J. Org. Chem., 2005, 70, 10737-10742.
A catalytic, direct asymmetric cross-aldol reaction of two different aldehydes in the presence of water is catalyzed by a novel combined proline-surfactant organocatalyst. Neither an organic cosolvent nor additional acid is necessary.
Y. Hayashi, S. Aratake, T. Okano, J. Takahashi, T. Sumiya, M. Shoji, Angew. Chem. Int. Ed., 2006, 45, 5527-5529.
Ketones, dienes, and B2(pin)2 undergo a stereoselective multicomponent coupling reaction in the presence of catalytic amounts of Ni(cod)2 and P(t-Bu)3. A subsequent oxidation furnishes 1,3-diols as the major reaction product.
H. Y. Cho, Z. Yu, J. P. Morken, Org. Lett., 2011, 13, 5267-5269.
Cu-catalyzed highly regio- and stereoselective 1,4-protoboration of dienylboronates provides unsymmetrical 1,4-bifunctional allylboron reagents. A subsequent chemoselective allylboration with aldehydes followed by oxidative workup give diol products with high diastereoselectivity.
S. Gao, M. Wang, M. Chen, Org. Lett., 2018, 20, 7921-7925.
A copper(I)-catalyzed asymmetric borylative propargylation of simple ketones offers broad substrate scope, good tolerance of functional groups, high diastereo- and enantioselectivities, and reaction robustness. The borylative product can also serve as a cross-coupling partner in Pd-catalyzed Suzuki-Miyaura reactions.
X.-C. Gan, L. Yin, Org. Lett., 2019, 21, 931-936.