Nonenzymatic Kinetic Resolution of Propargylic Alcohols by a Planar−Chiral DMAP Derivative:  Crystallographic Characterization of the Acylated Catalyst [J. Am. Chem. Soc. 1999, 121, 5091−5092].

Abstract

It has come to our attention that an oxygenated triterpenoid denoted saponaceolide A (see, e.g., De Bernardi, M.; Garlaschelli, L.; Toma, L. Vidari, G.; Vita-Finzi, P. Tetrahedron 1991, 47, 7109), while quite different in overall structure than mispyric acid, nonetheless has the same basic carbon skeleton. A biogenetic pathway essentially the same as the one proposed for mispyric acid has previously been proposed for saponaceolide A.We thank Prof. Giovanni Vidari for bringing this earlier work to our attention.

Gold(I)-catalyzed hydration of allenes

“…All reagents were purchased from major suppliers and used as received. Tridec-7-yn-6-ol,18 o -nitrobenzenesulfonyl hydrazine,19 ethyl 3-hexyl-3,4-pentadienoate,20 4-(4-(trifluoromethyl)phenyl)-3-butyn-2-ol,21 2,3-pentadienyl benzoate ( 2 ),13 1-phenyl-1,2-butadiene ( 4 ),13 dimethyl 2-(2,3-butadienyl)malonate ( 10 ),13 and 1-(benzyloxy)-2-(5-methyl-3,4-hexadienyl)benzene ( 16 )13 were prepared employing published procedures.…”

Nonenzymatic Dynamic Kinetic Resolution of Secondary Alcohols via Enantioselective Acylation: Synthetic and Mechanistic Studies

“…In previous studies, we established that a planar-chiral DMAP derivative serves as an effective catalyst for the kinetic resolution of a variety of racemic aryl alkyl carbinols, 8 propargylic alcohols, 9 and allylic alcohols 10 via acylation with Ac 2 O, providing selectivity factors as high as ~100 (eq 1). Our early attempts to develop a dynamic variant were stymied either by the incompatibility of the acylation and the racemization processes, or else by the need for elevated temperature in order to achieve racemization, which led to a substantial erosion in enantioselectivity.…”

6.08 Acylation-Type Reactions: Synthesis of Esters via Acyl Transfer

“…36,37 The selectivities are in a range between 3.8 and 20 and therefore synthetically useful. In contrast to aryl alkyl alcohols no additional base was employed, because the acylation of propargylic alcohols occurred under basic conditions in the absence of catalyst.…”

“…The selectivity for the KR decreases as the steric demand for the alkyl group of the substrate increases ( Table 4). 33,34,36 Catalyst (+)-28 was successfully applied the KR of allylic alcohols. A large variety of substrates can be resolved with good to excellent enantioselectivities ( Table 5).…”